That'd be awesome. I did mark all as read and have been using the clock, but I've never paid attention to if the clock is always right. It seems like it will let you go back to cached unless something has changed, which would be a good thing I guess. Until I changed the last thing, it did take me on a time travel journey to just hours ago when I first visited in firefox. It was quite a trip.
So I did isolate it down to being a firefox thing, it seems like what everyone has in common. The browser is being told not to cache it... if this is still happening I'm going to have to know what firefox version you guys are using so I can look into the release notes. It's clear it's some new change on their end and it may just be stricter enforcement of some kind of cache instruction that chrome is more lax about.
Please let me know if its better now or let me know browser version so I can take a look at it from that angle.