Fix issue #1264
diff --git a/system/database/drivers/interbase/interbase_forge.php b/system/database/drivers/interbase/interbase_forge.php
index 3f9967f..d1b006e 100644
--- a/system/database/drivers/interbase/interbase_forge.php
+++ b/system/database/drivers/interbase/interbase_forge.php
@@ -67,6 +67,14 @@
 		{
 			return ($this->db->db_debug) ? $this->db->display_error('db_unable_to_drop') : FALSE;
 		}
+		elseif ( ! empty($this->db->data_cache['db_names']))
+		{
+			$key = array_search(strtolower($this->db->database), array_map('strtolower', $this->db->data_cache['db_names']), TRUE);
+			if ($key !== FALSE)
+			{
+				unset($this->db->data_cache['db_names'][$key]);
+			}
+		}
 
 		return TRUE;
 	}