Bob, Nikon buys their sensors from Sony. They made one sensor for their D2H(s). No more.
Yes, I did leave out Dalsa (real big player) and Foveon (esoteric). Don't know where Fuji get their sensor from. May be they make it themselves. No clues about Panasonic and large sensors.
Look here:
http://www.leica-camera-user.com/dig...you-think.html
for a screen shot of the spectral response provided by Kodak for the sensor used in M8. The whole pdf file is on Kodak's site.
If that spectral response is really valid, then the M8 should not suffer from so much IR realted problems. It is really not a software problem. Interesting that Leica folks did not test the camera before its launch.