It is a firmware bug, and in this case we, the users, cannot help you. As @philipshabrook wrote, everyone experiencing the reboots should contact he Support, since if they do not get numerous reports, there is little chance anything changes. They need to collect data like the crashlog and memory dump found in the folder //GARMIN/Debug (they may lead you to install a small gcd file in order to allow the full log), since such bugs are very difficult to localize and to fix.
Some information how to proceed after a crash, is described on the Beta forum here:
I really don't understand why you can't grasp the concept of contacting Garmin support, instead of using the forums. Forums users can't help you. Can you not grasp that concept? And the fact that no other users are reporting this means your issue is unique to YOU!!! CONTACT GARMIN SUPPORT!!!
