tahoe stereo won't stay programmed

I purchased an 04 Tahoe 2 weeks ago today. The following day it wouldn't start so the dealer put in a new battery, the 4 wheel drive wouldn't engage either, so they installed a new 4 wheel drive panel. I have since discovered on 2 separate occasions that when I start the Tahoe, the radio is not programmed to the stations that I programmed it to. The first time, it was every station, this last time 2 of my stations were reversed, and when I started the Tahoe up, the station was on a different station all together and turned off. I watched the amps and they never changed, so I am leaning towards it not being the alternator, but I don't know? Any insight would be great, I don't want to keep bugging the dealer, but it has only been 2 weeks, any advise as to what it could be? Thanks

go back to the dealer and watever problesm u ot tell them to fix it asap.

is the radio factory?...don't crush the weasel...

Yes I believe it is factory, just a plain old cd player with programmable buttons, 6 I think. Thanks

Two possible answers. Your factory keyless entry is designed to change the radio to driver 1 or driver 2 depending on which key fob is used. See your owner's manual for driver personalization. The other possible problem is the main ground for the battery to the frame. Check the connection just above and to the driver's side of the driver's side front tow hook on the bumper. There are two ground wires there and the connection to the chassis is known to be poor unless someone has repaired it. A way to tell if the problem relates to a low battery or poor connections is if the radio clock resets. The presets are permanently stored in the radio unless you change them for both driver 1 and 2.sparky

Sparky, thank you very very much for your answer. I think you may be right about the driver one and the driver 2 thing. The first time I noticed it was when my husband was driving, and using his key, the second time he left his key in there and I took the tahoe, but only 2 stations changed, I will keep my eye on this to see if that is the case, I will have my hubby check the grounding wires and what not, see if anything looks odd. I appreciate the answers! I'm going out right now to read the owners manual, guess that is something I should have read first. Dawn