diff --git a/system/database/DB_driver.php b/system/database/DB_driver.php
index 6352c73..5f435e3 100644
--- a/system/database/DB_driver.php
+++ b/system/database/DB_driver.php
@@ -185,20 +185,19 @@
 	/**
 	 * Set client character set
 	 *
-	 * @access	public
 	 * @param	string
 	 * @param	string
-	 * @return	resource
+	 * @return	bool
 	 */
-	function db_set_charset($charset, $collation)
+	public function db_set_charset($charset, $collation = '')
 	{
-		if ( ! $this->_db_set_charset($this->char_set, $this->dbcollat))
+		if (method_exists($this, '_db_set_charset') && ! $this->_db_set_charset($charset, $collation))
 		{
-			log_message('error', 'Unable to set database connection charset: '.$this->char_set);
+			log_message('error', 'Unable to set database connection charset: '.$charset);
 
 			if ($this->db_debug)
 			{
-				$this->display_error('db_unable_to_set_charset', $this->char_set);
+				$this->display_error('db_unable_to_set_charset', $charset);
 			}
 
 			return FALSE;
@@ -645,17 +644,12 @@
 	/**
 	 * Determines if a query is a "write" type.
 	 *
-	 * @access	public
 	 * @param	string	An SQL query string
-	 * @return	boolean
+	 * @return	bool
 	 */
-	function is_write_type($sql)
+	public function is_write_type($sql)
 	{
-		if ( ! preg_match('/^\s*"?(SET|INSERT|UPDATE|DELETE|REPLACE|CREATE|DROP|TRUNCATE|LOAD DATA|COPY|ALTER|GRANT|REVOKE|LOCK|UNLOCK)\s+/i', $sql))
-		{
-			return FALSE;
-		}
-		return TRUE;
+		return (bool) preg_match('/^\s*"?(SET|INSERT|UPDATE|DELETE|REPLACE|CREATE|DROP|TRUNCATE|LOAD DATA|COPY|ALTER|RENAME|GRANT|REVOKE|LOCK|UNLOCK|OPTIMIZE)\s+/i', $sql);
 	}
 
 	// --------------------------------------------------------------------
@@ -1443,4 +1437,4 @@
 }
 
 /* End of file DB_driver.php */
-/* Location: ./system/database/DB_driver.php */
\ No newline at end of file
+/* Location: ./system/database/DB_driver.php */
diff --git a/system/database/drivers/cubrid/cubrid_driver.php b/system/database/drivers/cubrid/cubrid_driver.php
index cde719e..42f08fb 100644
--- a/system/database/drivers/cubrid/cubrid_driver.php
+++ b/system/database/drivers/cubrid/cubrid_driver.php
@@ -156,24 +156,6 @@
 	// --------------------------------------------------------------------
 
 	/**
-	 * Set client character set
-	 *
-	 * @access	public
-	 * @param	string
-	 * @param	string
-	 * @return	resource
-	 */
-	function db_set_charset($charset, $collation)
-	{
-		// In CUBRID, there is no need to set charset or collation.
-		// This is why returning true will allow the application continue
-		// its normal process.
-		return TRUE;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
 	 * Version number query string
 	 *
 	 * @access	public
@@ -362,12 +344,11 @@
 	/**
 	 * Affected Rows
 	 *
-	 * @access	public
-	 * @return	integer
+	 * @return	int
 	 */
-	function affected_rows()
+	public function affected_rows()
 	{
-		return @cubrid_affected_rows($this->conn_id);
+		return @cubrid_affected_rows();
 	}
 
 	// --------------------------------------------------------------------
@@ -801,4 +782,4 @@
 
 
 /* End of file cubrid_driver.php */
-/* Location: ./system/database/drivers/cubrid/cubrid_driver.php */
\ No newline at end of file
+/* Location: ./system/database/drivers/cubrid/cubrid_driver.php */
diff --git a/system/database/drivers/mssql/mssql_driver.php b/system/database/drivers/mssql/mssql_driver.php
index 25a32f3..2a4f2b5 100644
--- a/system/database/drivers/mssql/mssql_driver.php
+++ b/system/database/drivers/mssql/mssql_driver.php
@@ -138,22 +138,6 @@
 	// --------------------------------------------------------------------
 
 	/**
-	 * Set client character set
-	 *
-	 * @access	public
-	 * @param	string
-	 * @param	string
-	 * @return	resource
-	 */
-	function db_set_charset($charset, $collation)
-	{
-		// @todo - add support if needed
-		return TRUE;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
 	 * Execute the query
 	 *
 	 * @access	private called by the base class
diff --git a/system/database/drivers/oci8/oci8_driver.php b/system/database/drivers/oci8/oci8_driver.php
index 057095c..d9acaae 100644
--- a/system/database/drivers/oci8/oci8_driver.php
+++ b/system/database/drivers/oci8/oci8_driver.php
@@ -139,22 +139,6 @@
 	// --------------------------------------------------------------------
 
 	/**
-	 * Set client character set
-	 *
-	 * @access	public
-	 * @param	string
-	 * @param	string
-	 * @return	resource
-	 */
-	public function db_set_charset($charset, $collation)
-	{
-		// this is done upon connect
-		return TRUE;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
 	 * Version number query string
 	 *
 	 * @access  protected
diff --git a/system/database/drivers/odbc/odbc_driver.php b/system/database/drivers/odbc/odbc_driver.php
index c9aaa6e..fc4d1d3 100644
--- a/system/database/drivers/odbc/odbc_driver.php
+++ b/system/database/drivers/odbc/odbc_driver.php
@@ -123,21 +123,6 @@
 	// --------------------------------------------------------------------
 
 	/**
-	 * Set client character set
-	 *
-	 * @param	string
-	 * @param	string
-	 * @return	bool
-	 */
-	public function db_set_charset($charset, $collation)
-	{
-		// @todo - add support if needed
-		return TRUE;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
 	 * Version number query string
 	 *
 	 * @return	string
diff --git a/system/database/drivers/pdo/pdo_driver.php b/system/database/drivers/pdo/pdo_driver.php
index de2b0ab..90f0fd7 100644
--- a/system/database/drivers/pdo/pdo_driver.php
+++ b/system/database/drivers/pdo/pdo_driver.php
@@ -289,29 +289,13 @@
 	// --------------------------------------------------------------------
 
 	/**
-	 * Set client character set
-	 *
-	 * @access	public
-	 * @param	string
-	 * @param	string
-	 * @return	resource
-	 */
-	function db_set_charset($charset, $collation)
-	{
-		return TRUE;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
 	 * Version number query string
 	 *
-	 * @access	public
 	 * @return	string
 	 */
-	function _version()
+	protected function _version()
 	{
-		return $this->conn_id->getAttribute(PDO::ATTR_CLIENT_VERSION);
+		return $this->conn_id->getAttribute(PDO::ATTR_SERVER_VERSION);
 	}
 
 	// --------------------------------------------------------------------
@@ -510,33 +494,19 @@
 
 	/**
 	 * Insert ID
-	 * 
-	 * @access	public
-	 * @return	integer
+	 *
+	 * @return	int
 	 */
-	function insert_id($name=NULL)
+	public function insert_id($name = NULL)
 	{
-		if ($this->pdodriver == 'pgsql')
+		if ($this->pdodriver === 'pgsql' && $name === NULL && $this->_version() >= '8.1')
 		{
-			//Convenience method for postgres insertid
-			$v = $this->_version();
-
-			$table	= func_num_args() > 0 ? func_get_arg(0) : NULL;
-
-			if ($table == NULL && $v >= '8.1')
-			{
-				$sql='SELECT LASTVAL() as ins_id';
-			}
-
-			$query = $this->query($sql);
-			$row   = $query->row();
-
-			return $row->ins_id;
+			$query = $this->query('SELECT LASTVAL() AS ins_id');
+			$query = $query->row();
+			return $query->ins_id;
 		}
-		else
-		{
-			return $this->conn_id->lastInsertId($name);
-		}
+
+		return $this->conn_id->lastInsertId($name);
 	}
 
 	// --------------------------------------------------------------------
@@ -950,4 +920,4 @@
 }
 
 /* End of file pdo_driver.php */
-/* Location: ./system/database/drivers/pdo/pdo_driver.php */
\ No newline at end of file
+/* Location: ./system/database/drivers/pdo/pdo_driver.php */
diff --git a/system/database/drivers/postgre/postgre_driver.php b/system/database/drivers/postgre/postgre_driver.php
index 42329bd..89541e5 100644
--- a/system/database/drivers/postgre/postgre_driver.php
+++ b/system/database/drivers/postgre/postgre_driver.php
@@ -147,22 +147,6 @@
 	// --------------------------------------------------------------------
 
 	/**
-	 * Set client character set
-	 *
-	 * @access	public
-	 * @param	string
-	 * @param	string
-	 * @return	resource
-	 */
-	function db_set_charset($charset, $collation)
-	{
-		// @todo - add support if needed
-		return TRUE;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
 	 * Version number query string
 	 *
 	 * @access	public
@@ -712,4 +696,4 @@
 
 
 /* End of file postgre_driver.php */
-/* Location: ./system/database/drivers/postgre/postgre_driver.php */
\ No newline at end of file
+/* Location: ./system/database/drivers/postgre/postgre_driver.php */
diff --git a/system/database/drivers/sqlite/sqlite_driver.php b/system/database/drivers/sqlite/sqlite_driver.php
index 28c3cae..718501b 100644
--- a/system/database/drivers/sqlite/sqlite_driver.php
+++ b/system/database/drivers/sqlite/sqlite_driver.php
@@ -141,22 +141,6 @@
 	// --------------------------------------------------------------------
 
 	/**
-	 * Set client character set
-	 *
-	 * @access	public
-	 * @param	string
-	 * @param	string
-	 * @return	resource
-	 */
-	function db_set_charset($charset, $collation)
-	{
-		// @todo - add support if needed
-		return TRUE;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
 	 * Version number query string
 	 *
 	 * @access	public
@@ -667,4 +651,4 @@
 
 
 /* End of file sqlite_driver.php */
-/* Location: ./system/database/drivers/sqlite/sqlite_driver.php */
\ No newline at end of file
+/* Location: ./system/database/drivers/sqlite/sqlite_driver.php */
diff --git a/system/database/drivers/sqlsrv/sqlsrv_driver.php b/system/database/drivers/sqlsrv/sqlsrv_driver.php
index 9c50209..9b90381 100644
--- a/system/database/drivers/sqlsrv/sqlsrv_driver.php
+++ b/system/database/drivers/sqlsrv/sqlsrv_driver.php
@@ -144,22 +144,6 @@
 	// --------------------------------------------------------------------
 
 	/**
-	 * Set client character set
-	 *
-	 * @access	public
-	 * @param	string
-	 * @param	string
-	 * @return	resource
-	 */
-	function db_set_charset($charset, $collation)
-	{
-		// @todo - add support if needed
-		return TRUE;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
 	 * Execute the query
 	 *
 	 * @access	private called by the base class
@@ -424,13 +408,18 @@
 	/**
 	 * The error message string
 	 *
-	 * @access	private
 	 * @return	string
 	 */
-	function _error_message()
+	protected function _error_message()
 	{
-		$error = array_shift(sqlsrv_errors());
-		return !empty($error['message']) ? $error['message'] : null;
+		$error = sqlsrv_errors();
+		if ( ! is_array($error))
+		{
+			return '';
+		}
+
+		$error = array_shift($error);
+		return isset($error['message']) ? $error['message'] : '';
 	}
 
 	// --------------------------------------------------------------------
@@ -438,13 +427,25 @@
 	/**
 	 * The error message number
 	 *
-	 * @access	private
-	 * @return	integer
+	 * @return	string
 	 */
-	function _error_number()
+	protected function _error_number()
 	{
-		$error = array_shift(sqlsrv_errors());
-		return isset($error['SQLSTATE']) ? $error['SQLSTATE'] : null;
+		$error = sqlsrv_errors();
+		if ( ! is_array($error))
+		{
+			return '';
+		}
+		elseif (isset($error['SQLSTATE']))
+		{
+			return isset($error['code']) ? $error['SQLSTATE'].'/'.$error['code'] : $error['SQLSTATE'];
+		}
+		elseif (isset($error['code']))
+		{
+			return $error['code'];
+		}
+
+		return '';
 	}
 
 	// --------------------------------------------------------------------
diff --git a/system/libraries/Upload.php b/system/libraries/Upload.php
index 0b85323..ac29c1b 100644
--- a/system/libraries/Upload.php
+++ b/system/libraries/Upload.php
@@ -1,4 +1,4 @@
-<?php  if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
 /**
  * CodeIgniter
  *
@@ -593,16 +593,17 @@
 	/**
 	 * Verify that the filetype is allowed
 	 *
+	 * @param	bool
 	 * @return	bool
 	 */
 	public function is_allowed_filetype($ignore_mime = FALSE)
 	{
-		if ($this->allowed_types == '*')
+		if ($this->allowed_types === '*')
 		{
 			return TRUE;
 		}
 
-		if (count($this->allowed_types) == 0 OR ! is_array($this->allowed_types))
+		if ( ! is_array($this->allowed_types) OR count($this->allowed_types) === 0)
 		{
 			$this->set_error('upload_no_file_types');
 			return FALSE;
@@ -618,12 +619,9 @@
 		// Images get some additional checks
 		$image_types = array('gif', 'jpg', 'jpeg', 'png', 'jpe');
 
-		if (in_array($ext, $image_types))
+		if (in_array($ext, $image_types) && @getimagesize($this->file_temp) === FALSE)
 		{
-			if (getimagesize($this->file_temp) === FALSE)
-			{
-				return FALSE;
-			}
+			return FALSE;
 		}
 
 		if ($ignore_mime === TRUE)
@@ -640,7 +638,7 @@
 				return TRUE;
 			}
 		}
-		elseif ($mime == $this->file_type)
+		elseif ($mime === $this->file_type)
 		{
 				return TRUE;
 		}
diff --git a/user_guide_src/source/changelog.rst b/user_guide_src/source/changelog.rst
index cdb274d..ea96051 100644
--- a/user_guide_src/source/changelog.rst
+++ b/user_guide_src/source/changelog.rst
@@ -116,6 +116,13 @@
 -  Fixed a bug (#68, #414) - Oracle's escape_str() didn't properly escape LIKE wild characters.
 -  Fixed a bug (#81) - ODBC's list_fields() and field_data() methods skipped the first column due to odbc_field_*() functions' index starting at 1 instead of 0.
 -  Fixed a bug (#129) - ODBC's num_rows() returned -1 in some cases, due to not all subdrivers supporting the odbc_num_rows() function.
+-  Fixed a bug (#153) - E_NOTICE being generated by getimagesize() in the :doc:`File Uploading Library <libraries/file_uploading>`.
+-  Fixed a bug (#611) - SQLSRV's _error_message() and _error_number() methods used to issue warnings when there's no actual error.
+-  Fixed a bug (#1036) - is_write_type() method in the :doc:`Database Library <database/index>` didn't return TRUE for RENAME and OPTIMIZE queries.
+-  Fixed a bug in PDO's _version() method where it used to return the client version as opposed to the server one.
+-  Fixed a bug in PDO's insert_id() method where it could've failed if it's used with Postgre versions prior to 8.1.
+-  Fixed a bug in CUBRID's affected_rows() method where a connection resource was passed to cubrid_affected_rows() instead of a result.
+-  Fixed a bug (#638) - db_set_charset() ignored its arguments and always used the configured charset and collation instead.
 
 Version 2.1.1
 =============
@@ -137,7 +144,6 @@
 -  Fixed a bug - CI_Upload::_file_mime_type() could've failed if mime_content_type() is used for the detection and returns FALSE.
 -  Fixed a bug (#538) - Windows paths were ignored when using the :doc:`Image Manipulation Library <libraries/image_lib>` to create a new file.
 
-
 Version 2.1.0
 =============