I say this as someone who's never used any Soulseek client on any platform before, so some of these things might just be copied from a Windows app, and those often sorely lack in the usability arena:

1. The console is not where error messages should go, especially if the console isn't open by default. No [visible] feedback=bad UI.

2. No feedback *anywhere*. It's not possible to tell what the program is doing, if anything. It needs to trap console messages and produce user-friendly error messages, and show progess indicators (such as a throbber or an indefinite progress indicator).

3. All translucency should be off by default. Not only is it essentially unnecessary, I found that it made text in the window harder to read. It also substantially raises CPU requirements on pre-Quartz Extreme Macs if anything beneath the translucent window changes. Add eye candy only when it actually helps usability. Otherwise, just leave it out. ("But it's cool!" isn't a reason to sacrifice usability.)

4. The only acceptable spelling of "OK" buttons on a Mac is "OK". "Ok", "ok", "O.K.", "okay", "OKAY", "Okay", etc are not.

5. Don't bother with an "Apply" button in the prefs: either make the changes live, or apply them when the user presses OK. ("Apply" vs "OK" is something that confuses novice users to no end.)

6. Tabs should go on the top of the area they change, not below. (I am aware that Apple breaks its own guideline here sometimes, but that doesn't invalidate it.)

7. When something occurs in a window that's not open (e.g. choosing "Join the Mac Users chat room", which causes a tab to appear in the Chat window, which may or may not be open), that window should be opened (though not necessarily brought to the front if it's already open).

Please review the Apple Software Design Guidelines at <http://developer.apple.com/documentation/MacOSX/Conceptual/AppleSWDesign/index.html> and the Apple Human Interface Guidelines, at <http://developer.apple.com/documentation/UserExperience/Conceptual/OSXHIGuidelines/index.html>. Following these guidelines will substantially improve this app's usability and make it more approachable to the new user.