I considered that possibility. The problem that I keep coming back to is that even if the data does have to be reaquired, the coords haven't changed nor did my position. I should still be the same relative distance and direction from the spot that I'm looking for. At one stop, my GPS would have taken me across the highway about 300 feet when I knew by the hint that I was standing near the cache. Standing still, I turned off the GPS and then back on. After that the GPS wanted to send me about o.2 of a mile up into the woods ... a completely opposite direction.
I'm thinking it's time to contact "customer service."