In the forums, I've noticed a small problem. With the Site Discussion, just a minute after making a post, the PokéBall next to it is gray, meaning No New Posts, while other forums will have "New POsts" for up to an hour.
This is a limitation is 1.2 which would require a complete rewrite of the thread/forum tracking system. This has been addressed in MyBB 1.4. There is currently no time frame available for the MyBB 1.4 release, but it should certainly be out this year.