Same problem(s).

FWIW: I always go to the FT Miles board first. I then access the FT Travel board via the pull-down "Additional FlyerTalk Forums" menu. When I first access the Travel board, all of the folders are "lit", regardless of the true time/date of the last posts. I then access one of the forums and if there really are any new posts, only those threads will be lit.

I do not use the back button of my browser to go back to the main page of the Travel board - I use the "tree" menu and click on "FlyerTalk Travel". Going back to the main page this way then displays the forums' folders correctly: the forums that really do have new posts since my last visit are the only ones lit up.

Complicated, yes, but it works for me. Maybe accessing the Travel section from the Miles section is the key here, I'm not sure. If I access the Travel section directly, all of the forums are lit, but none of the threads.

Almost cocktail hour here in Paris - cheers!