Replacement GE JEM25 Also A Lemon

This microwave was a warranty replacement for the first one (reviewed, April '06). The first one lasted about 6 months, this one has lasted 10 months. It begins to to cycle on, then stops after 1 to 20 seconds producing either a blank display, error symbols, or PF (power failure). Sometimes the light goes out and it must be unplugged and plugged back in. It always looses its clock settings. It often takes 2 or more attempts to get 30 seconds of microwaving. Unfortunately, the problem is intermittent and when the GE repairman came today, it didn't happen (but, it did occur a few hours later). So, he did nothing but claim that there was a problem either with our electricity or the outlet! I'll be calling him back again, until it is fixed or replaced again. I wish we hadn't built-in the microwave because I'm stuck with this model.