Networking WIN98 & Server 2003

I'm having a problem trying to get my windows 98
workstations to authenticate to my windows 2003 network.
My domain controller is a WIN2k and the BDC is Server
2003, if I shut down the BDC I can authenticate to the
network using the 98 machines, but if the BDC is running
it says my passsword is wrong or access has been denied
to the network. I have added and removed the computer
from the domain, added and removed protocols, even re-
formatted, no luck....but one of my 98 machines logs on
just fine...I can't explain it, nor have I found any docs
on what the problem is. would appreciate any help.
Thanks
Aaron