After I had installed UT2004 on my Linux I've noticed about some issues I have.
The worst thing: I could not open the console (just with a keybinding - and only when I am in the game)
But now I have found out how to fix that:
1. Open the /System/ut2004.ini (for KFmod it is /kfmod20/System/KFMod20.ini) with a text editor
2. Search for:
[XInterface.ExtendedConsole]
ConsoleHotKey=192
EDIT: Sometimes even that doesn't fix the problem in KFMod, the solution: paste the same number in the section:[KFMod.KFConsole]
in the line
ConsoleHotKey=192
3. Replace the 192 with the decimal ASCII code for your key. For Germans it's the 246 for the Ö or the 94 for the ^ (see below)
BTW: Maybe It is also usable to change the hotkey for the small console input. just search for:
[Engine.Console]
ConsoleHotKey=9
Here the ASCII codes: