Forum View keeps popping back to first entry
 

I just updated from 3.8.1 to 4.0. Everything went OK (except for the expected mods failing), but it's not really usable because it will only show the first message in a thread. If I click on one of the replies, it shows for < 1 second and then flips back to the first message. I presume this isn't widespread or there'd be a lot more complaints, but I'd appreciate a hint about what to do to fix it!