This is most definitely a problem.
First of all, the problem that I noticed was that UT occasionally stutters after playing for a little bit.
But, the problem doesn't appear to be related to UT.
For example, right now, at the beginning of writing this post, I'm sitting at about 245MB of memory in use. The only programs I'm currently running are XMMS, KPPP, and Mozilla. There's no way that these three (in combination with whatever Linux is running in the background...drivers and whatnot) should take up that much memory.
As an example, after booting up completely, I was sitting at around 90MB of memory in use. I also looked at top for a few moments, and I could actually see the memory usage climb, by about 8kb/sec.
Finally, at the end of writing this message, I'm sitting at about 251MB of memory in use.
Has anybody seen a problem like this, or have an idea of how to fix it? I suppose I may have quite a lot of debugging to do...but I was hoping somebody else out there might have some hints...