For some reason the people designing the new version has two different implementations of “your discussions”.
If you go to the one under your “name box” in the right margin, it lists thread you have participated in from all forums. Threads are sorted by date of last post (except that if you have posted in a sticky thread, it stays on top no matter whether there are new posts in it or not). Only way I have discovered of seeing if there is anything new is to know roughly when you last read posts, and look on the list to see of any of the top threads have a “last post” date/time after your last visit - color doesn’t change.
There is also a tab on top called “Your Discussions” when reading each forum (e.g. the Model Railroader General Forum). In this list, threads you haven’t read since before the last post has a different color (dark blue) compared to those you have read - which are grey.
Not very logical that the same function is implemented totally different in two places, but there you have it. You can register it as a bug/issue in the Bug thread in the Community Assistance Forum of the trains.com group if you want to, and maybe someone at Kalmbach or at Telligent (the people who make the forum SW) will do something about it.
Smile,
Stein