Cannot connect to others on my network -- Warcraft III

[MiccyNarc]

I'm trying to play DoTA with some of the guys in my house at school, and I can't see their game when I host and vice versa. Works on my laptop fine and I can see their computer fine on Network places, can share files etc. but I can't play WCIII at all.

Windows firewall is disabled, it's the only firewall I have, and I'm using WinXP.

Advice?