Vista - WC III TFT joining games problem

hey, when im at my friends house, i can join games hosted by other people on battle.net , but when i try to join his games that he hosts on battle.net it comes up with the message "this game cannot be found, please check that youve typed the name in correctly blah blah blah" it seems to be only me who cant join, any ideas on how to fix it? we play on bored aussies and we've checked that site for fixes, but the suggestions they had didnt help.
thanks

His ports are not forwarded correctly. Make sure you forward ALL ports correctly.

1) Windows Firewall
2) Router Firewall
3) Modem Firewall (if you have one. This is the one most people don't know about and the reason why they cannot host. and there reason I couldn't for a long time)

Windows firewall forwarding should be easy enough to figure out.

Router firewall: Look up your ip and gateway (usually 192.168.1.1 or something along those lines). Type in gateway in the address bar of IE or firefox. Forward ports 6112 - 6119 depending on what you have it set on and make sure it is the host's ip address being forwarded.

Modem Firewall: In the router customization there may be a second gateway and ip number. Mine looked like 10.62.xxx.xxx (x's being numbers i dont remember) or something along those lines. Forward just like the router.

That's what got mine to work hopefully yours too.