I had my surgery on 4.25.07 and also experienced the shoulder pain. Often it is paired with back discomfort on my left side. For myself, I find that it is usually associated with eating or drinking too much, too fast. I'm pretty sure it's gas pain. The first 2+ weeks, it was pretty severe.

I find that when I start to get it, if I stop eating and drinking immediately and start moving around (stand up and walk around), then it usually doesn't get so severe. It's been over a month since my surgery and I still get it sometimes, but not nearly as often.

Best of luck. If the discomfort continues, make sure you discuss it with your dr.