We've identified the source of relogin problem, and in fact it was to do with our recent update on Friday night. It was a similar problem to the one we had before, where we were hitting our 15 cookie limit for the site and cookies were thus being deleted to ensure no more than 15 cookies were present. Where were all these cookies coming from? Each advert was setting a cookie recording when you last saw the advert (the idea being that it's possible for us to then not show that advert for x minutes), anyway this isn't necessary and we've turned off this feature so no cookies are created for ads, and therefore the site shouldn't reach it's 15 cookie limit and remove any cookies (such as the ones that keep you logged in!). Because cookies are persistent, then don't get removed when you close your browser, you may wish to clear out all your cookies, close your browser and repon it to make sure that the ad cookies no longer exist.