Just resting it is pretty foolish advice, imo...you need to correct the issue, not just ignore it. Take a look at Bill and MR's article here:
http://www.t-nation.com/readTopic.do?id=1426252
Realize though that a corrective exercise is only as effective as how it's performed...if you're having true shoulder pathology, you may very well need to consult a professional, such as a physical therapist, one-on-one so that he/she can help you improve scapular positioning and proprioception/mobility problems.