Today flying to Chicago at FL260, I had a total loss of GPS signal. Both the GTN750 and 650 went out at the same time. Has this ever happened to anyone else? RAIM prediction was good for the flight. I did have the software updated this week and this was the first long flight since having that done but hopefully that did not cause it. It came back after about ten min and had no issues remainder of flight. Anyone else have this happen? It is somewhat disconcerting when that happens.