We have to set the time that stuff expires, and we expanded the default time by quite a bit, IIRC, but I do understand your problem.
I access this site via no less than 3 different computers on a a daily basis, and I have a similar problem.
I dunno if this helps or not, but if you click the "Quick Links" pull down menu, you can see a link called "Today's Posts"..........
....... this will show all of the posts in the last 24 hours, if they have new posts in the threads or not..........
Does that help at all?
The pessimist complains about the wind; the optimist expects it to change; the realist adjusts the sails.
William Arthur Ward