Forums problem: keep getting logged off

[Malrubius]

Until a day or two ago, every time I've come to this web site (since December!), I've been automatically logged in (I (still) have the "remember my password" checkbox checked ).

But now, if I visit another site and come back, I am logged off and have to log back in. Sometimes it seems to happen even if I don't leave the site at all, but just go from the forums back to the home page.

It could be something that changed here on my machine, but I can't think of what. Then again, it could be a server-side change.

Has anybody else had this start happening recently? Any ideas about what would cause it?