NFS autentication ?!? Need help.

[dud]

I am exporting a directory using NFS.
the entry in /etc/exports is:
/export (ro)

(/export is the directory and ro is read-only permission)
But now I´m using a windows nfs client and when I try to mount (map) the drive it asks me for a username and password and I can´t use the linux accounts for it. It only accepts the username nobody with no password.
Why can´t I use a valid linux account?
How can I change that?
How can I add different permissions for different users?
Any help (or link with documentation) will be very nice.
Thanks in Advance.

[ccieToBe]

I'm having a simular problem. So far I've found out that the *nix box needs to have PCNFSD installed (in FreeBSD anyway) in order to authenticate Windows users. It came on the FreeBSD CD, but I'm having some trouble getting it working. I'll play around with it and let you know what I find out. Let me know if you figure it out.