Hey guys, I'm having issues with my Zumo 665. It will work fine for a while, but then I get some high-frequency squeals and crackling sounds from the speakers. If I rest the device for an hour, the cycle repeats. Garmin tech support has told me the equivalent of "reboot" so far (master reset, re-patch device), which has been unhelpful. Anyone go through this? Anyone find a resolution, other than warranty replacement through Garmin? Thanks!