For whatever its worth-----I was having problems losing my dial up connection recently resulting in similar happenings (not just on ACMOC). Had my computer "guru" check the computer out-----replaced the modem, and so far am not having the disconnect (log off) problems.
Interesting enough----nothing showed to be wrong with the modem. But we changed it out anyway while he was here----looks like that was my problem.
In my situation-----I would try to post a reply, etc. only to find that I was no longer logged on the site. Would check my dial up connection----and was no longer connected to the server.
Regardless of your problem-----its gotta be really frustrating.
Avon, Ms 38723
D2 5U and other scrap iron