Has anyone had any problems with their engine mounts or the control module that serves them?

My 06 HAH is in the shop now for the third time on this issue. It is basically a vibration that I feel, especially in ECO or ASST mode, usually at light throttle. You can feel it in the steering wheel, the pedals, the seat, etc. Kind of feels like starting a stick-shift car off in third gear instead of first.

The first time I brought it in, around 1500 or 2000 miles, they diagnosed and replaced the front engine mount. (this is the electronic mount that is supposed to cancel out the vibrations of the engine in 3-cyl mode). The problem got better, but returned again around 5,000 miles. The dealer this time said that it was "normal operation" and that there was no problem.

However, today, at around 7,500 miles, the problem was much worse, so I drove it over to the dealer, they are now working on it. The tech who went for a ride with me at first thought it was a transmission problem - said that there is a "first gear unloading valve" or something like that that causes trouble - thought maybe they needed to change the trans fluid. But after plugging the car into their diagnostic equipment, he decided that the problem was with the engine mount after all. So they are troubleshooting the engine mount and its control module, and in the meantime, I am driving an el-strippo Chevy Cobalt.

I am curious if anyone else has had trouble with the engine mounts, or this transmission problem that the guy was hypothesizing about.

Alec