Try, first, a hard-reset - hold down all three (3) buttons on the surface of the unit ( remember the "mute" button? yep, I'd almost forgotten it existed, having used the SmartCord exclusively :
: ), and then cycling the power to the unit.
This will initiate a reset, and you should see the display show with your unit's current firmware.
Many times, this can effectively cure simple "hickups."
Remember to go through and re-set all of your user preferences, as they will be themselves reset to default.
If this doesn't work, give Escort's C/S a call, that's the best way to do it, instead of any of us here guessing at how much it will be, or even if it can be done at all.
Best of luck!