Called Floscan's tech support today to get a few answers on Kevin's problem. The rep basically said if you're running and older unit with a 265(green top) sensor, plan on it failing if you use low or ultra low sulfur diesel.
The 265 is one of the early sensors and the diaphragm isn't compatible with the new diesel. No replacement sensor in the works, you need to pony up and buy a new system. Oh happy joy, break out another hand full of Franklins.
Mike