There are some shops which can repair the damaged sensor even though Leica will not. You just gotta love those guys in Leitz and their sterling customer support. I know a fellow who can delaminate and replace the sensor cover which, IIRC, is the problem. There is no doubt that Leica and their satellites should be handling this and I do believe they are not.
If I am wrong about Leica not repairing the M9 sensors I sincerely apologize. If I am not wrong I stand by what I have written. And fanboys, please do not pile on with a "blame the victim" jeremiad. It is so inappropriate to defend this company behavior with any argument. A simple, "Yeah, they should fix this" would be way more appropriate. It is a lovely camera and the end of the line for CCD sensors. Leica purports to be the best but their behavior on this subject does not indicate a quality company. A good company would fix those sensors with corrosion regardless. You either stand behind your product or you do not. They were all new once and they were all sold with faulty sensors. rant/
I guess you all know how I feel on this subject. Mine has a factory replaced sensor and came that way, used. So I am not arguing to advance my case but that of others.
Cheers