Fix ./system/database/drivers/oci8_driver.php to pass the configured database character set on connect.
diff --git a/system/database/drivers/oci8/oci8_driver.php b/system/database/drivers/oci8/oci8_driver.php
index d4adfd5..d4c27fa 100644
--- a/system/database/drivers/oci8/oci8_driver.php
+++ b/system/database/drivers/oci8/oci8_driver.php
@@ -79,7 +79,7 @@
 	 */
 	function db_connect()
 	{
-		return @ocilogon($this->username, $this->password, $this->hostname);
+		return @ocilogon($this->username, $this->password, $this->hostname, $this->char_set);
 	}
 
 	// --------------------------------------------------------------------
@@ -92,7 +92,7 @@
 	 */
 	function db_pconnect()
 	{
-		return @ociplogon($this->username, $this->password, $this->hostname);
+		return @ociplogon($this->username, $this->password, $this->hostname, $this->char_set);
 	}
 
 	// --------------------------------------------------------------------
@@ -136,7 +136,7 @@
 	 */
 	function db_set_charset($charset, $collation)
 	{
-		// @todo - add support if needed
+		// this is done upon connect
 		return TRUE;
 	}