Close services after using them, added dbutil->backup() method
diff --git a/system/database/drivers/interbase/interbase_driver.php b/system/database/drivers/interbase/interbase_driver.php
index 33038ad..b49d1fa 100644
--- a/system/database/drivers/interbase/interbase_driver.php
+++ b/system/database/drivers/interbase/interbase_driver.php
@@ -139,6 +139,9 @@
 		if (($service = ibase_service_attach($this->hostname, $this->username, $this->password)))
 		{
 			$version = ibase_server_info($service, IBASE_SVC_SERVER_VERSION);
+			
+			// Don't keep the service open
+			ibase_service_detach($service);
 			return $version;
 		}