[Leica] ever clean a KM Scan Dual?

[Harvey.Arche at jp2hs.org (Arche, Harvey)]

I'm reluctantly coming to realize that part of the problem I'm having with 
the grain in some of my thinner/evening exposures is coming from the 
scanner, which is giving me a big fringe of noise (?) on the long edges, and 
a very consistent chunk on a short edge of frame 6. Its affecting all of my 
scans, but most visibly the negs with large open areas.

Has anyone here ever attempted work on a KM scanner? I'm using a Scan Dual 
IV, but have an older model #II I'll practice on first, if it comes down to 
it. Google hasn't nettedme  anything yet, and our archives only has 
suggestions on how not to kill your Coolscan.

Marty, I forgot to mention when I posted them, that the obvious night shots 
from the 'Union Hill' set were P3200 (1600) done in Xtol 1:1, instead of my 
usual 1:3. Going to that dilution, and changing the brand of distilled water 
I used, took care of the contamination problem that was giving me spots. 
Don, I had every intention of giving it the pre-wet you suggested, but when 
it came time to actually do it, I was so locked in to my routine I spaced it 
out.

I'll be out of town for a week, and don't know what sort of web access I'll 
have where I'm going, so if I go silent it won't be the usual 
rudeness/laziness.

Arche