Using XP Pro clients in an NT4 domain

I have an NT4 network and just got a new PC with XP Pro installed. I joined it to the domain fine, but the XP client does not seem to inherit the user permissions from the NT4 server (ie. when I run a setup.exe as a domain user, the XP client first asks me to authenticate as a local admin. Then when trying to browse the shares on the NT4 server from inside the setup program, no shares are visible.) I can browse the server from My Network Connections and can see the shares fine (and map drives).This one has me stumped.

Shaun Crass