Contraints on Armature Cause Game Engine to Crash and Slow Down

I tried the game forum but people don’t seem to know anything about it.

Am I the only one who has tried a non Auto IK’d armature with manual IK and Floor contraints in the Game Engine only to find that the game engine always crashes when contraints are on the armature?

Plz just read the first and last post that I made on this thread link: http://blenderartists.org/forum/showthread.php?t=87977

and tell me if you know anything about it

thanks