I've been having this problem for a while now: often in thread lists the titles change to bold without anyone having written anything new or edited any posts in the thread.
I often spend days checking and re-reading all these threads to make sure that there is nothing new (some threads are even one or two or three years old) and after re-reading them they go back to normal without bold.
After a while this problem repeats itself and I have to re-read half the forum all over again.
It is really very annoying.
Is there something wrong in the settings that may be causing this problem or is it a database defect?