shares on one server only are really slow to access

Hi all!

Heres my problem;

My network consisted of two standard 2003 sp2 servers, one provided file and
print and was a bdc and the other used as a PDC. The clients are around 30
XP sp2 and 15 or so Vista business PC's. The file and print server was an
older server and was indentified to be replaced. The time came to replace
the server and so I bulit a new 2003 standard and fully updated it. I have
DCPROMO'd it and made it a DC and have also moved the FSMO roles assigned on
the old server to the new server and used the MS file migration utility to
move the data/shares and permissions to the new server. After I was sure all
was working I demoted the old server and decommissioned it. All clients
(including Vista) can log on ok and the XP PCs can browse all data shares on
both servers instantly, but the Vista PCs can only browse shares on the PDC
instantly, the shares on the new server take minutes to display and even
longer to open a file.

I have looked at the MS KB and found the 2003 sp2 issues and insured the
hotfix has been applied to both servers, and also the articles relating to
RSS etc. All of these have been applied to no avail and is really becoming a
problem.

I therefore turn to you all in the hope that someone may be able to offer
some advice!

Many thanks in advance.

Paul

PS apologies for the cross post, I just wanted to cover my bases.