I have:

OS: Mandrake Linux 9.2
Video Card: ATI Radeon 9500 Pro 128MB
RAM: 512 MB
Motherboard: Asus A7N8X Deluxe (nForce 2)
CPU: AMD Athlon XP 2500+
Sound Card: Built-in nForce 2 SoundStorm

I have sound in everything else but ut2004. The sound works just fine in Windows but not in Linux. Anyone know what I should do?

are you using alsa or oss? do the command
lsmod
as root and post the output here.

[root@localhost daniel]# lsmod
Module Size Used by Tainted: P
fglrx 197384 116
agpgart 53508 15 (autoclean)
nvaudio 39412 2
ac97_codec 15828 0 [nvaudio]
soundcore 6340 0 [nvaudio]
af_packet 14856 1 (autoclean)
sr_mod 17016 0 (autoclean)
floppy 55932 0
nvnet 30656 0 (autoclean) (unused)
3c90x 27468 1 (autoclean)
nls_iso8859-1 3484 1 (autoclean)
ntfs 77292 1 (autoclean)
supermount 84032 2 (autoclean)
ide-cd 34052 0
cdrom 32608 0 [sr_mod ide-cd]
ide-scsi 11376 0
scsi_mod 105792 2 [sr_mod ide-scsi]
usb-ohci 21080 0 (unused)
usbcore 74988 1 [usb-ohci]
rtc 9228 0 (autoclean)
ext3 60048 2
jbd 39360 2 [ext3]

hmm... i cant tell... try downloading the latest alsa packages from here:
http://alsa-project.org
and installing them, and see what happens.

whoa i have sound now!!! before i had changed the driver from snd-intel8x0 to nvaudio thinking "i have an nvidia card why do i have intel drivers?" I found out now that the nvaudio is OSS and the snd-intel8x0 is ALSA. I changed it back and now it works. Someone needs to write a "linux sound for dummies book" cause I still don't know what's going on with all this. I'm starting to really think now that that nVidia Unified Driver that I installed really didn't do anything.

ut2004, as well as pretty muc all of the ut games, use alsa, and not oss. oss is becoming obsolete, so its a good idea to upgrade to alsa. glad to hear you got it working .