Most likely is that mods/admins found some of your comments that they thought were spam and deleted them. Another that could have happened is that a user you have talked to before deleted all the comments on their page, or they got banned. Those would be the 2 most likely reasons to lose AP.
Well it was probably just a little glitch, that has (in times past) happened to me many a time. Either that or some comment/posts may have been deleted because said mod/admin considered it spam. Another possibility would be that someone/some people were clearing out their comments or something and several of yours were deleted in the process.
I may as well explain myself whilst answering another question you might have in the future. The reason I posted is because the forums tend to lag a little and I didn't hard refresh the page (contro + F5) before posting.
