When autowork engages the popup is there but stays until you've clicked...which you don't do because of autowork. Consider a timer on the popup...and make it popup x amount of time before autowork re-engages! give them warning.
It appears if I have gotten the blocked page, I can reload the url (alt-d ) and the block is removed! I'm not sure what conditions are necessary to recreate this...I've only seen it a few times. Maybe an issue with the change to the autowork.