I've never managed to get the KDE mixer working properly, so you'd best follow OneAndOnlySM's advice. If that doesn't fix it, and zinf is the only app acting up, feel free to try my general solution to all problems linux-y: compile from source.

You'll need this, this, and possibly this.

Do the first one (libMusicBrainz) first, and then the second (zinf). If it complains about needing GDBM then do the last one and try the second again, if it complains about needing something else then install that and try again.

For each tarball you're installing, tar zxvf <*.tar.gz>, cd into new directory, type "./configure", then if that works type "make", and finally switch to root ("su") and do "make install".

There's no garantee that this will fix the problem, but when I get an app misbehaving and can't find the fault being reported anywhere else, it's the first thing I try. Good luck.