I've just noticed one possible problem that will result in system slowdown.

Anytime I have Limewire open with its window showing and in the background, and have another window in front of its window, the "Window Manager" process jumps to a steady 50%-60% %CPU usage. (This is on a Yikes! G4 400@450 w/ 1GB RAM). Window Manager is the process that's responsible for creating and updating the image that's shown on your screen.

Seems like something funky is going on with window refreshing. It could be a Java thing and not even be Limewire's fault. It looks like this is the problem that I've been experiencing for quite some time. It makes sense now, that the Window Manager process is hogging all the CPU cycles. That's why I'd never get the 1 second updates while running "top" in the terminal. Top may well have taken the sample but Window Manager was too busy with other stuff to show me. Running Quartz Debug (one of the Developer Tools applications) confirms this and shows Limewire's window and the layered window constantly being updated.

My recommendation is to keep Limewire's window in front of everything else, and when you need to switch to another application (the Finder for example) hit Command+H to hide Limewire's window. Then to switch back to Limewire, click its icon in the dock.

Hope this helps....