Great analysis, JoB! It seems like a workaround to the 403 problem is pretty easy... Until There's A Cure (tm).
I got repeated 403 errors about 10 days ago, when I was trying to send someone a PM. It didn't involve pen-icillin (I never had the occasion to use that word on the Forum till now). However, since we were discussing health issues, I used the word "pill." Could it be another P-word?
EDIT: No, "pill" seems to publish without a problem.
Well, now that we know to be on the alert, and we're saving copies of any text we post/PM, it shouldn't be too hard to catch other instances of the 403 problem if it recurs.