Well at least you're stable. Luckily while gaming your temps are a lot less, in my case about 10C less. Try running a game, after 10 mins minimize or close it and open Afterburner, check what the graph shows for frames and temps to see if it's fairly stable and how hot it is. Personally I don't know that I would be comfortable running that hot, but my card is different (Sapphire 5850).
Also, just a tip, instead of running the GPU OCed all the time, make a profile that is just the stock settings, and then from the try icon you can load up the OC profile to game but otherwise use the stock one to keep temps down and prolong life.