slow network discovery of shares in a workgroup

have a vista beta 2 workstation and an XP Pro SP2 workstation on a workgroup
network.

Prior to upgrading to vista when using XP in Explorer I could type the
standard unc \\myxpbox\share and It would come up right away. Now with
Vista it takes almost 1 minute before it comes up. I have user restrictions
on the XP shares, but I am logging into my vista box with the same username
and password (just like before on XP), so it won't promt for credentials. I
am running my basic network just using the 2 machines and a linksys wireless
router.

Any suggestions on things to try to speed this up? It does it every single
time even if I've already connected to the XP box. And once I can see the
files transfering them is fine, just if I closer explorer and then reopen it
takes another minute to find the shares.