Eeeek. I really can't get on AIM right now because I'm on my bro's windows account (he's letting me on for a little bit)...
But umm... Try disabling any firewalls that you have. It really helps to go through a network wizard and select one to be a gateway and another to be connected through a network and to use the other computer as it's internet gateway. Also, set up all networks with the same workgroup name.
I have to go soon, so if ya could post a little more about the situation, then I could probably be of more help when I get back on.
Happiness is not about being perfect.
It is about seeing beyond the imperfections.