I cannot run nexuiz on fullscreen. I have tried several things including vid_fullscreen 1, vid_restart, setting the fullscreen option as Yes in the menu, however the game stays in windowed mode

This never happens in any other game and I'm wondering is there a way to get it fullscreen, the reso i use in game is 800x600 while desktop is 1280x1024, i use reforce to keep my Hz at 800x600 to 100Hz, however my monitor supports that setting

any help would be appreciated

what OS are you using? also have you tried using the nexuiz SDL binary? also what video card do you have?

color depth in Nexuiz and the general settings (means Desktop) should be similar. So if you run Nexuiz with 16-bit and the general setting is on 32-bit (or the other way round), this could be the reason for trouble.

using nexuiz-sdl.exe instead of nexuiz.exe really could fix that

I guess Urmel.dll is right but more like the other way round.. Nexuiz is set to 32 bit by default and i guess calvinL's desktop is set to 16 bit. Honestly i have no idea why windows is so picky about this..
You can change your colors depth for the desktop if you right click on the desktop, choose properties and go to the last tab of the window that should appear then. You find the setting there.