Wow okay, I think I can actually stay logged in for real this time.
Thanks for the information.
Sorry for the delayed response. I kept getting taken to the login page after every button click or page change, and couldn't get to any part of the forum interface that would let me post without asking me to log in again. This is the 3rd time I've typed this message up.
I checked the "Keep me logged in" box last time, so here's hoping it posts this time.
[update]
Okay it worked.
Maybe something is set up weird in my browser because if "Keep me logged in" is unchecked on this site's login page, it goes into "log me out the instant I do anything" mode.