Strange VPN issue

[xaqq]

Hello,
I've set up a VPN using OpenVPN on Ubuntu Server. The server runs as server-bridge.
We're 3 friends, me (named A) and I have Windows Vista. The second (B) uses Windows XP. We both use OpenVPN client-side as a VPN client.
The last one (C) has a Mac and uses TunnelBlick as a VPN client.

After being connected on the VPN we’re able to ping each other so the VPN seems to be ok. But, something strange happened after, while trying to play Warcraft III using the local network.
If me, (A) create a game (B) will be able to see it and we’ll be able to play but (C) doesn’t see it.
If (B) creates a game, we’ll both (A and C) able to see his game but not join it (I think it’s a problem on his computer but, whatever, it doesn’t matter).
If (C) creates a game, (B) will be able to see it and join it. But me (A) won’t see it.
It seems that me and (C) aren’t able to see each other but we can ping each other.

Can you help me with giving me tips or info?
Thanks and sorry for language mistakes!

 

[sturm]

Start by turning off firewalls on all 3 to rule out problems there. Can you see any drives that are shared on the other computers?

 

[xaqq]

Hi,
Thanks for your answer, we've have turned off our firewalls but the only thing which changes is that (B) is now able to host a game.
Yeah I can see my friend's drives, and they can see mine too.
The thing which is very strange is that it works fine with one of my friend and not with the other.

Do you have an idea ?