T60P vista home wifi, shared but invisible

[cheeebs]

i've shared the whole computer and individual drives and folders, made everything shared, discoverable, etc., yet only my XP machines appear in my workgroup. the vista machine won't appear even with different settings. i can map to my XP machines from it (it's online), but not to it since it won't appear in any dialogs. i've opened up as much as is obvious in the network & sharing center as well as properties dialogs w/in explorer. is there some tip someone can give me about Vista that i'm missing to get this box in the home workgroup?

thanks.