I had left xolox running for approximately 10 hours, with 3 searches running. Throughout this time, xolox used a good chunk of my cpu. At the end of this 10 hour period, xolox was using 100% of my cpu. After this 10 hour period, I tried to task-switch to xolox, and I was not able to switch to it. I decided to force windows to shut it down, after which doing so, appoximately 185MB of memory were cleared up.

There is something seriously wrong with this software.. I would think that it must be more than simple memory leaks. ?

A program like MemTurbo will help your RAM usage (there are many places you can get a copy).
There are a lot of Xolox users ready to try the new Xolox 1.13, whenever it will be available (I hope all of the minor annoyances will be fixed).
Also, it is not recommended that you leave searches running for more than 2 hours (even though I often leave mine on over night too).
Xolox is still my favorite share utility, despite a few manageable problems.

As soon as I start xolox it runs at 97% cpu or higher. It does work and I have been successful downloading large files. It seems to find what I am looking for better than other programs that I have tried too! But it's performance is flakey. After a while all communication will stop yet the cpu is still maxed. When I exit the program it still stays resident burning cycles until I kill it. It does manage to reconnect and continue the downloads once re-started.

I am running Windows 2000 on a 1Ghz Athlon. I'm hopeful that the next version will fix this bug.