Golflogix locks up

Question

I have been using the Golflogix GPS unit for 3 months and recently it started locking up when I'm on the course. When I turn the unit on, I am not able to push any buttons to wake up the unit. I have remove the batteries to turn the unit off. I then have to download the courses again and I can usually get through one round without it locking up.

Any advice? A friend of mine bought the same unit when I did, and his unit has done this once,