Well I've picked my brain, and looked at every resource I could find, but to no avail can find a solution.

Basically, I have my 4 character all up and running. Randomally, i have one, always the same character, same computer disconnect.

What I have tried:

New Cat6 cables
New Router
New Switch ( using a Cisco 2950 now )
New Nic card ( i have tried 3com, Intel, Dlink, etc.... )

I really have no idea why it is doing this. I can stay connected for mabey 20-30 seconds and it gets disconnected. Always the same computer / character.