I am running Ubuntu 10.04 and Extreme Tux Racer. For some reason, the Impulse Tracker music files skip a bunch of notes. When I play them in an Impulse Tracker player, they are just fine. The version in the repositories, which I am using, is 0.4-2ubuntu1. The music is really annoying.
My PC Specs:
nVidia GeForce 210 w/ 2 Monitors
2 GB RAM, 2 GB swap
2x AMD Anthlon 64 X2 Dual Core Processor 5000+ (x86)
500 GB SATA HDD
Not quite sure on my sound card. Apparently it is Realtek, but my motherboard is nVidia and it lists 2 or 3 sound devices.
Some unspecified time before now (at least a few months ago), it works fine.