When you try to save an object, but the database does not exist, Doctrine throws a Doctrine_Transaction_Exception exception with the message "Rollback failed. There is no active transaction.".
But the real problem is that the database does not exit. The problem is in the Doctrine_Connection_UnitOfWork class around line 146:
The exception occurs because of "$conn->rollback();", and so the "throw $e;" is never reached.
We should probably throws an exception earlier about the fact that the database does not exist.