I had the same problem with my 2010 Sirrus Sport, but I thought the grips on the 2011 version were the newer ones with a set screw? Maybe not.
I tried 3M spray adhesive and that worked for about a month, but then they broke loose again. I've heard hairspray can help but honestly don't see how it would be better than the 3M spray. Plus you lose adjustability with adhesive solutions.
I gave up, took them off, and put on Ergon GC3s instead, and that was money well spent.