Had very similar problems (bad buttons, lots of menus and such not working, no sound, etc) yesterday when I activated the KDE unstable repo. Did an update this morning and almost all the problems are gone. I would venture a guess the KDE team was busy shuffling things around. Try an update, its looking much better now.
Beautiful KDE4 by the way. I am running both KDE 3.5 and the "trunk" (or as close as I can get without compiling it myself, thanks to our awesome KDE team!
) version of KDE 4.2 beta. It's absolutely awesome! Man, now Aqua on OS X looks so "00"y
Oops. Y2K bug.