Even though it's fixed, as a guess, it's related to what happens in Access when you attempt to open an object in design mode when it's already open from VBA.
Next time you think about it, start stepping thru a function and then try to open up the QBE Wizard. Access will give you some nonsense error essentially saying the wizard doesn't exist. Stop/Cancel the code suspended function and you'll be able to open the QBE again.
Mike