FC3 or FC4?
If FC4 go get the 4 rpm's from www.sama.org
for sama-3.0.20 (download to Desktop and (rpm -U packagename12 3 4)
turn off the seleinux for smbd and nmbd by clicking check boxes on in the Security / Fire wall gui.
(This version will be out for FC4 soon and you can update it to use SElinux and relabel then but the older version of Samba are just too buggy to deal with.)
After updating go to www.samba.org
and read How-to-install Samba-3.020 article on the front page (This is also in the How-to forum.)
Remeber W2K use classic security model by default, and XP uses (guest, restircted, everybody) type model.
Meaning you need to set the security (users and rights) on W2K shares to something Linux can deal with.