Okay, maybe I've answered my own question?

It appears that unless I check the "Remember me?" box near my username and password when logging in, I will get logged out constantly.

Bit weird. I'll try to get used to it. On other websites I've used clicking "Remember me?" just means it's easier to log in though and isn't there to prevent one from getting logged out constantly.

On other websites, if one doesn't click "Remember me?" it just means your session times out in an hour or so if there isn't any onsite activity -- rather than to be logged out after each click to a new page.