Touchpad woes (by 2 users)

My JGR8850 range has now history of 4 repairs of the touchpad; error message F1-8. Last two times the service technician replaced the controller as well, bringing the bill to some $750. Can this be related to the particular unit that I have, or this is a known design flaw? (hopefully remedied in the latest versions?) The problem is rather bothersome, because the periodic self-diagnostics in the range causes it to start beeping spontaneously, which results in 3-4 weeks of misery. We have to remember to shut the poor thing down each time we finish cooking (the cooktop works, the oven does not). The range is under 3 year extended service agreement by Sears, which means the repairs are free, but Sears won't replace it with a new one unless it fails 4 times a year. I am running out of ideas how to fix this.