Simply put, increase the angle of your dangle. You probably have your straps too low and aren't keeping about a 30 degree hang. Try raising your straps up on the tree, it should help. A little experimentation with new grear is always fun.
"If you play a Nicleback song backwards, you'll hear messages from the devil. Even worse, if you play it forward, you'll hear Nickleback." - Dave Grohl