Revert previous commit
diff --git a/system/database/drivers/interbase/interbase_driver.php b/system/database/drivers/interbase/interbase_driver.php
index 4044c45..aeea00d 100644
--- a/system/database/drivers/interbase/interbase_driver.php
+++ b/system/database/drivers/interbase/interbase_driver.php
@@ -310,11 +310,7 @@
 	public function insert_id($generator_name, $inc_by=0)
 	{
 		//If a generator hasn't been used before it will return 0
-		if($id = ibase_gen_id('"'.$generator_name.'"', $inc_by) !== 0)
-		{
-			return $id;
-		}
-		return ibase_gen_id('"'.$generator_name.'"', 1);
+		return ibase_gen_id('"'.$generator_name.'"', $inc_by);
 	}
 
 	// --------------------------------------------------------------------