A gear question: Summicron 28mm ASPH

Unusual for me to ask an equipment question as I normally just post images. However I have been keen to try the 28mm focal range for a little while (nothing to do with its ability to cut out cookies) and was all ready to buy one, when I read about the red edge problem that some people have experienced.

I have found a used one for sale which looks in great condition and was recently serviced by Leica. According to the serial number it was manufactured in 2000. I think this is the first year that the ASPH was made.

I'd like to know a bit more about the lens and the also the problem on the M9 as I am not going to be able to try the lens before purchasing.

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Regards
  Guy