Network Problems: One Client cannot see the other or someone cannot access this client

Network Problems: One Client cannot see the other or someone cannot access this clienthttp://developers.de/blogs/nadine_storandt/archive/2007/04/02/Network-Problems_3A00_-One-Client-cannot-see-the-other-or-someone-cannot-access-this-client.aspxWeekend experience :) Me and my boyfriend wanted to play a game over network, but we get in trouble. The first problem was I cannot see the laptop of my boyfriend in the network, so i thought something is wrong but where?? The next problem we come inenCommunityServer 2008 SP1 (Build: 30619.63)