SEVERAL ppls on ONE router

[Tomisama]

the problem is mtw and gamespy both want specific ports open,

i cannot forward the same port to multiple computers without data corruption between the different "players"

Only the host computer has router ports directed to it's self, to allow for that hosting to happen. The other computers in the game (on the same side of that router or not) are not the host, function as players only, and do not need ports (router ports) forwarded.

You must learn how to be a host first, before you consider anything more complicated.