I have the same issue right now and it is brand new, I haven't changed anything in my settings nor on my computer, without being an expert I'm still a really experienced and pretty advanced computer user. I've checked settings, checked similar problems on the firefox help and various forums, found nothing that seemed to match this exactly or that worked for me. It's only on Google by the way, any other session is perfectly saved. If I do a search using the quick search on the top right, I'm never logged in, and when i log in right then and I do a quick search I'm automatically logged off for some reason even though I was on that same page a second ago. I haven't figured out the pattern either but sometimes when I do a quick search I even land on a blank google search page - well, the google search homepage basically with no search entered even though I did one. It's not life-threatening but it's fairly annoying, any solution? :)