narfbg suggested fixes
diff --git a/system/database/drivers/interbase/interbase_forge.php b/system/database/drivers/interbase/interbase_forge.php
index 177433f..6301481 100644
--- a/system/database/drivers/interbase/interbase_forge.php
+++ b/system/database/drivers/interbase/interbase_forge.php
@@ -1,13 +1,13 @@
-<?php  if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
 /**
  * CodeIgniter
  *
  * An open source application development framework for PHP 5.1.6 or newer
  *
  * NOTICE OF LICENSE
- * 
+ *
  * Licensed under the Open Software License version 3.0
- * 
+ *
  * This source file is subject to the Open Software License (OSL 3.0) that is
  * bundled with this package in the files license.txt / license.rst.  It is
  * also available through the world wide web at this URL:
@@ -39,7 +39,6 @@
 	/**
 	 * Create database
 	 *
-	 * @access	public
 	 * @param	string	the database name
 	 * @return	bool
 	 */
@@ -55,7 +54,6 @@
 	/**
 	 * Drop database
 	 *
-	 * @access	private
 	 * @param	string	the database name - not used in this driver 
 	 *	- the current db is dropped
 	 * @return	bool
@@ -69,7 +67,6 @@
 	/**
 	 * Create Table
 	 *
-	 * @access	private
 	 * @param	string	the table name
 	 * @param	array	the fields
 	 * @param	mixed	primary key(s)
@@ -171,16 +168,11 @@
 	/**
 	 * Drop Table
 	 *
-	 * @access	private
 	 * @return	bool
 	 */
 	public function _drop_table($table)
 	{
-		if ($this->db->db_debug)
-		{
-			return $this->db->display_error('db_unsuported_feature');
-		}
-		return array();
+		return 'DROP TABLE '.$name;
 	}
 
 	// --------------------------------------------------------------------
@@ -191,7 +183,6 @@
 	 * Generates a platform-specific query so that a table can be altered
 	 * Called by add_column(), drop_column(), and column_alter(),
 	 *
-	 * @access	private
 	 * @param	string	the ALTER type (ADD, DROP, CHANGE)
 	 * @param	string	the column name
 	 * @param	string	the table name
@@ -237,14 +228,13 @@
 	 *
 	 * Generates a platform-specific query so that a table can be renamed
 	 *
-	 * @access	private
 	 * @param	string	the old table name
 	 * @param	string	the new table name
 	 * @return	string
 	 */
 	public function _rename_table($table_name, $new_table_name)
 	{
-		$sql = 'ALTER TABLE '.$this->db->_protect_identifiers($table_name)." RENAME TO ".$this->db->_protect_identifiers($new_table_name);
+		$sql = 'ALTER TABLE '.$this->db->_protect_identifiers($table_name).' RENAME TO '.$this->db->_protect_identifiers($new_table_name);
 		return $sql;
 	}
 }