Win98/Windows2003 query

We have a problem with Windows98 machines on our
Windows2003 domain.
We had a Win98/Nt4 domain which we have upgraded to
Windows2003. We had a problem with logging on to the
domain but this was fixed by installing the DSclient.

We have a recurring problem accessing resources eg
printers on the win98 machine. We can see the Browse
listing but when we try to attach to the resource, it
asks us for a password.

Any ideas on this weird problem?
Cheers