Unreal Tournament 2004 won´t run

[AndersNo1]

Or, actually the game runs perfectly. When my network cable is plugged in that is. Once I remove it and try to boot the game it merely starts with the first image and then goes down again within seconds. I´ve tried to make the game boot using wireless network and even mobile modem but the same thing happens. I suppose it locks to my IP-nr but I should be able to play Single Player mode without internetconnection, right?
Thankful for any help!
I run it on Mac OS 10.4.11 on my powerbook pto.

[DICKSTER]

You might have to reinstall the whole game?
Dickster-------just a guess-------

[AndersNo1]

Nope, solved it - it was the screenresolutions fault. It was set to high since I run it on another screen usually. When disconnected from that screen the laptop won´t run the game since it has poorer resolution.