Bug when moving posts between threads.

I'm having some wierd problems in some topics.

A week ago I had one user digging up 4/5 threads conserning the same player, when we already had a new thread about him.

I closed the old ones and started moving/deleting the posts from those topics and over into the newest thread about this player.

Now the strange things started happening, some of the threads that I emptyed whent descended to the place they should be (from a lastpost-date prespectiv) but some of them dident descend to where they belong, but stayed up on page one as if they had just been posted in...
Even tho the last post in those threads was way old.

Another strange thing is when I move posts that dont belong in the thread they were posted and into a new one(create a new thread from the move-post window) the new thread is not localated where it should be (from a lastpost-date prespectiv)