I had a two sensor setup working flawlessly and when I left for vacation for 6 days, I come back with some problems. It seems that one of my sensors is not reading. I had a USB extension on that one, and I tried it without the extension, and it still doesn't read. One of them reads perfectly in every USB slot on my computer but the other doesn't. I can do 1 sensor setup perfectly. It's not showing up at all. Not saying if a USB isn't compatible, not no loading circle thing, no X. Just nothing.