RADIUS domain stripping

I've successfully managed to get RADIUS configured and it's working very well for all but one thing... I'm trying to configure Windows Vista to use single sign-on. I can get all of the configuration working properly on that end but when I use that it sends the domain with the username to the RADIUS server. I can't seem to figure out what I need to do to convince RADIUS to strip the domain. My only other option seems to be to have the Windows logon show two different username and password fields, pretty ugly and not intuitive for our users. Has anyone done this using the built in FreeRADIUS? What might I be missing? The only things changed from default at this point are I turned on logging of the usernames so I coudl see a little more of what was going on. I also used radiusconfig -addclient to insert our cisco wireless devices...