Just going through my old post and saw I never replied back to this. Well GV's CS back in 2010 was garbage and not that helpful. Basically the code got scrambled probably from the battery having a low charge. They recommend I call a Locksmith but it would cost more than what the safe was worth. They also told me they would tell me the location of the solenoid as a worse case to open up the door. I opted to cut the bad boy open and stick my hand in it and reset the unit. It was a major hassle, i would not recommend buying one of their safes. If it had an alternative key lock like most of their smaller units it would have saved me much headache and hassle.
In short unless they have included a key or method to reset the combo with out having to have internal access to the safe I would stay away from it.