Painkiller on LAN

[tyrs4u]

Hey there... Okay my best mate is staying here for a week & I noticed he has Painkiller on his laptop & asked him when he bought it & has he tried it online so I figured hey we both have that game I like it online why not he & I play via LAN? Well we get this weird message when trying to join a game whichever oe of us made the game we see "Error the key is invalid according to GameSpy?" Something like that...? What's that all about? I know we both legit copies & sure we use a fixed EXE so we no longer have to use out CD's.. or whathaveyou... Could that be it? Should we try getting the original exe that was backed up & get it running?

I mean it made no sense hen I saw the Gamespy thing being involved when we are LAN not over the net? Any help please??