There they determined that it seemed to be an inflamed bursa that was causing the problem (which was the diagnosis the last time this happened). While they sent me in for an x-ray, the primary treatments include a 5-day course of prednisone and trying limit shoulder movement. The main concern was that its been about three weeks since the initial flare-up until this more recent one; however, it was suggested that might be because I was still using the shoulder and had taken myself off of anti-inflammatories too soon.
Hopefully I'm on the mend. The low-level pain has been making me crabby--when added to the stress due to the end of the all the work turned in at the end of the semester and my lack of progress on my dissertation, I have been significantly more waspish than normal. In truth, I just want to be able to raise my arm again.