Thx, all. Apparently this is a relatively common problem after doing a search on teh internets
Looking at your picture the thin ring between the spacer and cassette looks like the one between my original dork disk and cassette when it was on my Korso's. Why are you using both instead of 1 thicker spacer?
Clean your cassette
you can use the mavic 9sp spacer from mavic to use with a 10sp cassette. I tried it without the shimano 10sp spacer and just the mavic 9sp spacer, but there was noticeable play.
1.85mm spacer according to my calipers.