What's up with my Garrett Pro-Pointer AT???

My Garrett Pro-Pointer AT has been acting up. At first, for some reason I thought it was a battery issue. Apparently it was not. My problem is not consistent. At times it works just fine and then it doesn't. I turn it on and you hear the start-up beeps, I attempt to pin-point and nothing. I have to press and hold the button until it goes into the sensitivity option mode and and reselect the highest sensitivity. I hear the 3 beeps, I let it time out, it goes into the detect mode and then it works just fine. Any suggestions other than contacting Garrett? Thanks to all for taking the time to read this.