Vista & XP Gaming via router

Problem is that Vista and XP can't find each other when gaming via
router. I tried to play Grand Prix 4 on LAN with TCP/IP but it doesn't
work. Vista finds session made with XP but cant connect. XP doesn't even
find game made with Vista.

Computers finds each others at network places. They have same workgroup
and they share files and connections are ok. Weird is that i have 3
computers (Vista, XP, XP) connected to router and XP machines
multiplayer in Grand Prix 4 works fine. I just tried to connect Vista
& XP computers with cross-over cable and multiplayer worked fine! Looks
like Vista can't communicate with XP via router?

I also turned firewalls off but no help.


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Jy1ppy