Quote Originally Posted by Duke John
This flickering is that for example an arm that suddenly has an extreme position and then pops back into the right position? I have this with a gun reloading animation. I thought that it was caused by extreme rotations of a bone which causes problems for the R:TW engine.
Yep, there was a discussion on the TWC forums about this some time ago, and this was pretty much the conclusion we came to.

The only fix was to lessen the ammount of rotation on the offending bone at the frames it happened on. Pain in the rear.