I too was having that problem and i wrote a couple of emails to some people. One of the responses i got was from Ryan (over at icculus.org) and he said that any OpenGL application that was compiled for 32bit will NOT run on 64bit at all. Regardless of what lib's you have installed. OpenGL will only run on the system it was compiled for - i.e. 32bit. I sure hope UT2004 will have a Linux64 build (they will have a windoze 64bit build but forget about that).
Gentoo Linux-64, AMD64 Athlon 3200, Asus K8V Deluxe, 1 gig(3200 400mhz) ram, GeForce FX5200 128, HP 400i DVD+R+RW, HP ScanJet 2200c, Epson Stylus C84, JVC DRV3000U (firewire - usb), Kodak CX6330