I did not have this problem with Samba when I was running W2K but evidently I cannot use Samba's version of SMB with Windows 2003 server. I get the following message:

cli_negprot: SMB signing is mandatory and we have disabled it.
26595: protocol negotiation failed
SMB connection failed

Evidently Andrew feels this is a problem with SMBFS, http://lists.samba.org/archive/samba/2003-December/076388.html,  and we should move to CIFS. The bad news is that CIFS is supported in the 2.4 kernel via a patch. The 2.6 kernel supports CIFS. I guess I will put this project off until Fedora Core 2 is released. I have other options if this becomes an issue.