Taking a guess ... I'll bet that the site that holds the posting software (aka ranchero.com} has a rule that says they will log you off the site if you don't respond over some time interval. This site will log me off instantly if I shut down my computer, or other-wise lose contact with the board. Running linux here, but that's fairly standard behavior. Have you attempted to open another window to log in, and left that running while you did something else?
Once I've logged in on any day, I can delete the window (Google Chrome) and come back later in the day without having to log back in. The next day, however, I must log in again. Not a big deal, but unexpected.
I have passwords saved for all my other sites that are automatically entered when I log in, except for this site. I don't understand why. It's not a big deal, but is it the way this site is set up, or my 'puter?
Mine started doing this last week. No changes on my end so I think something is going on with the site server. Greg