slow network discover on workgroup network

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.