added removal of non-printing characters to escape_str() of drivers that do not have native PHP escaping mechanisms
diff --git a/system/database/drivers/mssql/mssql_driver.php b/system/database/drivers/mssql/mssql_driver.php
index 98c03c5..5ac90b4 100644
--- a/system/database/drivers/mssql/mssql_driver.php
+++ b/system/database/drivers/mssql/mssql_driver.php
@@ -214,7 +214,7 @@
 	function escape_str($str)	

 	{	

 		// Escape single quotes

-		return str_replace("'", "''", $str);

+		return str_replace("'", "''", $this->input->_remove_invisible_characters($str));

 	}

 	

 	// --------------------------------------------------------------------