Aimoo relies heavily on the *today* function to point out new posts.  The new post icon also points out a category that has new posts.  Sadly, there is no bolding to indicate new activity on a post.  So it happens that if someone edits a post, the edit doesn't show up in the *today* list, nor is it indicated with the *new topic* icon.  I am trying to point this out to them.   For now, it is something we need to be aware of.