Recalibrate screen on Roadmate 700?


I am guessing this can't be done since there is nothing in the manual, but my touchscreen on my Magellan Roadmate 760 does not respond to touches to the upper right corner. Does anyone know if the screen can be recalibrated?

Magellan Maestro 4250, T-Mobile G1 with Google Maps, iPaq with TomTom, and a Tapwave Zodiac with TomTom and Mapopolis