I've done this everyday for a long while now. I never have shoulder probs (knock on wood).
CFT: Are you taking any joint support supps? I use Osteo Bi Flex and apply Skeletal Balm to my knees and elbows. That combo works great for me along with 15g of fish oil daily.
Maybe try sleeping on your back too. Your sleep posture can cause all kind of problems. If you sleep on the same side for eight hours a night, after a few months you will most definitely be jacked up.