Just wanted to let you know WinMX works fine in wine under SuSE 9.1 and KDE (tested in 3.1, 3.2.1 and 3.3)
I don't know about CrossOver, I might test it in a while, but I expect it to run under CrossOver too
The only thing is that it sometimes doesn't allow me to select items and the "taskbar" for IM and chat windows isn't working (I need alt+tab to enter them, the in-app taskbar buttons don't seem to do anything)