multiple missfires in all cylinders?

I just helped a friend with his 2006 h3 who was experiencing the same type of problems. It would stall when stopping at red lights and wouldn't idle for more than two minutes. We talked to the local dealership and the recomended the cylinder head repair or throttle body replacement. I bought a 8$ can of throttle body cleaner and 10$ can of mass airflow sensor cleaner, I removed the plastic housing leading to the throttle body and cleaned it with the spray cleaner and the MAF sensor as well. It runs and idles like new again. This seemed to be a common problem with this model and this process is recomended every 10k miles.

Have a 2006 H3 and bought it brand new. At 51,000 miles there was a crack in the radiator and had to replace it. At 57,000 miles a head went out and now at 62,000 miles the transmission went out!!!! This vehicle has been well taken care of and I have done all of my services at Hummer since I got it, including oil changes. The only off road it has seen has been trips to the ski mountain, the rest of the miles have been normal driving to for work and a few road trips. After I pay the $3000 theywant to put a new transmission in it, I will finish out the winter driving with it and its time to get rid of it! Love the H3....may I just got a lemon