[Road Runner]

I know this thread is about WAW but i think it will be interesting to all.
i have big LAN problem

me and my frends played united offensive with no problems until one day I could not see hosted games from one specific computer and that computer cannot see games when I am hosting, but everybody else can ..... and the weirdest part is that we don't have that problem with some of the maps.
We are using 1.4 patch and 1.51 for united offensive, playing throught hamachi 1.0.1.5

I am getting quite frustrated.
please help