"New" button not working properly

[CuriousParty]

Over the last couple of days I've noticed that the new button does not seem to be working for me consistently. It does not happen in every thread , but in several that I follow I hit "new" and am taken to a much earlier post that I have already read.  It's always the same post in the specific thread, and some of them are now posts several days back.

I've tried loggin out / logging in, and I've tried "mark all as read", but the problem comes back. Any ideas?