9/10 speed on older wheels?

Can I just put a 10 speed cassette on my 2002 Open Pros with DA hubs or my 2002 Ksyrium SSLs? Or are those hubs not compatible with 10 speed cassettes?

Thanks,
-Colin

If there a 9 speed hub, 10 speed fits.

10sp cassettes work on 9sp hubs with a thin spacer.

10sp wheels will not take 9sp cassettes.

I was wondering the same thing I notice that my 10sp has a little rattle to it and I figured I needed a spacer. What size spacer is this. I tried to look for the spacer but I could not find one, could someone help me out? Or should my LBS have it in stock?
Nick

I believe the spacer should have come with your cassette.

Shimano Part No.: Y-1Z8 07000 Low Spacer (t = 1.0 mm)