Cassette rub

What is the hub? If the hub was serviced recently the spacers may be out of order.
See if Shimano: http://www.shimano.com.au/publish/content/australia/en/cycling/customer_support/service_diagrams.html

hub is ultegra 6500. without tear down things seem to be in order, but perhaps i should dissasemble and take a peak. wheel was "new" but bought from individual, front still had tag on it but rear may have been mounted, may have not been. THings look pretty clean aside from dust though. Is it possible that the dropout is a bit bent and i can't tell? ive never put together a 9 speed system, how much clearence between then lock ring and the serrated lock nut (part that hits the drop) is there supposed to be?

Its in the link. I fitted a wheel with a Ultegra 9 speed, (600), and rebuilt the axle with new cones and balls, the PDF has all the spacer layout.
http://www.shimano.com.au/publish/content/australia/en/cycling/customer_support/service_diagrams/road_bike_service.MainContentPar.0008.Schematic.0006.File.tmp/fh_6500_ev.pdf
http://www.shimano.com.au/publish/content/australia/en/cycling/customer_support/service_diagrams/road_bike_service.MainContentPar.0008.Schematic.0022.File.tmp/cs_6500_si.pdf

Thanks for the help. I got out a torque wrench and cranked it down to the required 40nM and there is now paper thin clearence, but the wheel spins freely. THe drop might be a bit bent, and the frame has pretty fat welds. If the clearence remains a problem I will first add spacers to the axel and then if that does not work i will file the weld down a bit. Additional bending of the stays is not an option as it is an aluminum frame. Frame spacing should be 130, as it is a 2000 Klein Quantum Race that should have come with 9 speed on it. Well anyhow, thanks again.
Kev