Vista and Linksys VOIP wireless router WRTP54G

I have this Vonage phone/wireless & wired router setup that currently works
in wired mode with two different XP laptops. I connect the coax from the
cable outlet to my cable modem, an ethernet cable from the cable modem to the
Linksys router, and another ethernet cable from the router to the laptop. I
power-up the cable modem first and let it get itself set, then the Linksys
router. The XP laptops are set with TCP/IP set to acquire IP addresses
automatically, and this works fine - they can see the network and IE works
and all that. However, a new laptop running Vista connected exactly the same
way says it finds an unidentified network and won't connect. If I remove the
Linksys router from the setup and run the ethernet cable directly from the
cable modem to the laptop, the network connection works fine.

Any ideas?

Thanks!