Apparently the current difficulties of Kodak have adversely affected Leica as well. The 18 megapixel sensor on the M9 was made by Kodak. But their sensor division was sold to Platinum equity in 2011. That seems to have caused a shortage of these sensors. Many owners of M9 cameras that were sent to Leica for sensor repairs received delay notices. To speed things up, cameras sent in for sensor repairs were in some cases replaced with brand new M9s as a result of this shortage.
Let's hope that Platinum Equity will be able to supply sufficient amounts of sensors soon to eliminate this shortage.