I had the same type of problems with my first pn-40 but after being out in the middle of the woods with low batteries for about the 3rd time that same day I ended up putting the batteries in backwards and smoked the thing up.(and boy did it smell) (I thought the jeep was on fire) LOL. Got another one a few days later and havent really had any problems with this one. I also own a few garmins and I do like my oregon for geocaching but when out in the middle of the woods hiking or jeep'n I'll take my pn40 any day of the year. I just know that I MUST KEEP fresh batteries on hand. LOL.