The above was happening to me. Unfortunately, I went off a good size table top jump with my shoulders still square to the board, which got me off balance in the air, which resulted in a nice slam and partial shoulder separation.
Since then, I switched to the Extremecarving/Swiss/rotational style of riding that keeps my shoulders about parallel to the board when going straight. This way, I ride my alpine board and freestyle board the same way.
This season I've only ridden my freestyle board once. But I've been hitting the straight jumps and pipe with my alpine board (Donek FCII 163).