I was reading on the ktm950 info website about the nuts on the early ones not having a washer built in, they were upgraded on later ones.
Seem 2003/4 year 950's were affected but later ones should be fine.

http://www.ktm950.info/how/Orange%20Gar ... djust.html

I've looked at all the external ones on my bike and they don't have washers build in (that I can see anyway) - is this an issue on the later 990 SD's?