YEh.. but what if the NIC is disabled in the hardware profile?

Ive had some PC's from new.. where the Nic is disabled.. default install... normally the user has a Dialup modem in the machine.. ..

So have you checked in this area?.. strange.. but could be your problem..

i know they work cause when i plug my dsl modem cable
is this saying the PC connects to the DSL Modem with out a hitch?
so is it just when connecting PC to PC for file TXfer?

So from your old setup the difference is only the new PC?
Go with the other idaes of the X-over cable.. just because it worked before dosent mean that the new nic is happy with the setup..or the older nic may not be happy with the setup..