Shoulder Pains When Squating?

Lately, I have been experiencing shoulder pains when I squat. I have tried to mix up some various grips, but it has not helped much. Would anyone be able to help me out with this one? Is there any stretches or other exercises I should be doing to relive this pain?

Thank you.

I’d shoot Mike Robertson and Eric Cressey either a PM or post this question on their Locker Room threads. If you have access to a Safety Squat Bar and/or Cambered Bar, I’d imagine that would help alot. Also, Dave Draper has an attachement which can turn a normal bar into SSB, or at least very close to it.