ESU

Hi, I have a '10 GC with the 730N RER nav stereo system. A few months back I had an issue with it dimming all by itself. You would start the car up in the morning and you couldnt read the screen. After an hour or so it was fine. Next day you would start the Jeep and it would be fine, a very intermittent problem. I brought it to my local Chrysler Dealer ( Manfredi ), generally not a very helpful place. They told me it was an adjustment? They couldnt tell me how they adjusted it or how to explain how it would dim and go brighter without me touching anything but it hasnt happened in the 2 months since then. Last week the screen froze while my wife was using the bluetooth/phone feature. The screen was frozen with her last call info and stayed like that even after you shut the car off. After an hour of restarting and shutting the car I had to disconnect the battery to get it to shut off. It has worked fine since then. My concern is that my warranty is up this March and I dont want to have to go for a grand 4 months from now after the warranty is up. I called Manfredi this morning and they dont seem too be very concerned. They have told me to bring it in next week. SHould I be worried? Is this thing going? SHould I insist they replace it? Thx, Cory