well I doubt there is such a feature and using
vb beta would not cause this. You would have needed to run the scan database feature realign username on photos comments to cause this. I do not beleive you can delete photos in bulk belonging to no userid so your only way to do this would be to issue some query in mysql like so to some bogus userid
UPDATE pp_photos SET userid=9999 WHERE userid=0
You could then go to the userid 9999 profile and use the delete all photos function