I can’t really think of a reason why it will not work for you, especially considering you have success with all the other apps.
I see you are experienced from your sig. So I’m confident you haven’t overlooked anything obvious.
You are using amarok from the factory repo and not backports aren’t you?
Like I said, I overwrote the disk. I’m a distro-hopper and currently I’m using Ubuntu as my “stable” (I mean, it has held the same distro for a MONTH now! That’s stable!) distro but looking at doing a shift-around so as to get openSUSE back on one of my laptop’s hard drives and possibly server.
In Gnome, Rythmbox is actually doing pretty well and it’s very easy to add Fluendo to Gstreamer for MP3 playback.
Reinstalled Amarok, still didn’t work, deleted .kde4/share/apps/amarok/, and all the Amarok config files in .kde4/share/config/ restarted Amarok and now everything is working.