Any ideas what the difference is between REV E and REV E2 ISS transmitter boards, both being the 2009 version of the board? The logic chip has a 2.0 on it on the REV E 2 board. I purchased my Pro 2 in April 2009 and it has the REV E. I just purchased a new ISS from Scaled Instruments and the new one shows this REV E 2.0. There is a definite layout change to the board, but appears to house the same capacitor that likes to leak and cause for the need of replacement as it has prompted me to replace my unit. This also happened to me last year with my anemometer transmitter board, that the capacitor leaked and caused it to stop working after 4 years. Both the last year replaced anemometer transmitter board and the ISS I am replacing were purchased in 2009. I am not sure if the new anemometer transmitter board on last years replaced unit has the same REV E 2.0 board that this new ISS does. I will check tomorrow.