Another XP <--> Vista networking struggle

[fling1]

I'm sure you'd rather not see this question again, but here's what I have for you:

1) Home network of 2 XP machines and printer connected to Syslink router (connected to cable modem/router). This has been working fine and continues to work fine. Both machines have been recently updated to SP3.

2) New laptop in the house (thanks, Santa) with Vista Home Premium, wireless. New laptop can see the internet and the printer. (aside, but interesting maybe: on XP network printer is shared through first computer. second computer knows about printer only because it sees it as a device of first computer. Vista machine sees it as a network device, independent of either XP computer. hmmm.)

3) Workgroups are the same for all three.

4) Vista network is set to 'local' and all sharing options are 'on'

5) except 'password protected file sharing' which is 'off'

6) All firewalls are off for now.

7) XP machines can both see the Vista 'public' folder and access the test file I put there.

8) Vista machine can NOT see either XP machine, nor any of the shared folders they offer.

9) XP machines to not show up in Vista's windows explorer, nor on the network list, nor on the network map, even as a non-mappable item. They just aren't there.

What else should I do to make the XP shared folders visible to the Vista laptop? Thanks in advance for any assistance.

-Derek.