I've had the same thing happen to me. I injected 1 cc sust in the delt, and it went in fine. After inecting, I noted a lump, even after massaging it in (did so for 5 minutes). I worked delts that session, and didn't notice a whole lot of difference. That night, about 6 hours later, it was swollen up (not baseball size, though). I woke up later that night in pain. That pain lasted for 4 days. I'm also very into the aseptic technique, and proper cleansing.
The thing is, the same thing happened when I pinned my other delt.....I figure it was a reaction to something in the gear in s relatively small areas. I just switched to glutes and its tolerable....THE GEAR IS CERTAINLY WORTH IT!