dwyloc: Sorry to wake up a really old thread but it looks like this has now been fixed.
I just purchased Unreal 2 yesterday as its on the Summer Sale along with the original Shadow Warrior as 2 different classic fps games I was missing form my collection, anyway the good news is the GOG Galaxy installation included Both Single player and the Multiplayer MOD for UnReal 2.
So now I just need to work out how to update the default master server, as the one configured with my install no-longer seems to exist and I will be ready for some on line Multi-player Unreal 2 action, or find some friends for a lan game ;-)
Can you please check the install folder and see if the two are together or separate?