The function that allows for abuse reporting (the X) was the culprit behind the mass un-publishing and re-publishing (and sending out of notification emails...) of comments and forum topics. It did it again...it unpublished more than 4600 approved comments from unregistered or un-logged in users. So I've had to reset it, and now it should be ok. If you do see anything odd, or comments approved that shouldn't have been, please let me know. Thanks! :)