We're constantly getting a disk read error on the nav system in our 07 X Sport. I have a homemade nav disk in the unit with 2009 maps. My guess is the disk unit is failing and not the disk. Thought I would just switch back to the original disk to see if that fixed anything, but since the maps were older the system rejected the disk. Sometimes we just get an error and I switch back to the radio display and all is well until it freaks again. Other times, the whole system reboots. The error is more annoying than anything since I NEVER use the nav system because it's crap.Is there anyway to disable the system? I'd rather not spend the money for a new disk unit for a system I never use. Or am I stuck with the annoying errors?