Amarok crashes when "populating playlist"

[J Nash]

Hi all!
I'm using Feisty Fawn and installed Amarok.
When I click on some music it goes on to "populating playlist" and gets
stuck there. I can still can use Amarok but the populating stays for
ever. After a while it gets "black and white". I suppose it's a
feature of Ubuntu when apps are not responding.
Sometimes I get a crash from KNotify.
I suspect it's something to do with mp3 support as one time before it
crashed, it showed a little window saying that I hadn't that
installed.
Below follows the output of starting it from the console and the
KNotify backtrace.
Thanks.

$ amarok
X Error: BadDevice, invalid or uninitialized input device 169
  Major opcode:  147
  Minor opcode:  3
  Resource id:  0x0
Failed to open device
X Error: BadDevice, invalid or uninitialized input device 169
  Major opcode:  147
  Minor opcode:  3
  Resource id:  0x0
Failed to open device
Amarok: [Loader] Starting amarokapp..
Amarok: [Loader] Don't run gdb, valgrind, etc. against this binary!
Use amarokapp.
X Error: BadDevice, invalid or uninitialized input device 169
  Major opcode:  147
  Minor opcode:  3
  Resource id:  0x0
Failed to open device
X Error: BadDevice, invalid or uninitialized input device 169
  Major opcode:  147
  Minor opcode:  3
  Resource id:  0x0
Failed to open device
kdecore (KAction): WARNING: KAction::insertKAccel( kaccel = 0x8096918
): KAccel object already contains an action name "play_pause"
QLayout "unnamed" added to QVBox "unnamed", which already has a layout
kdecore (KAction): WARNING: KAction::insertKAccel( kaccel = 0x8096918
): KAccel object already contains an action name "play_pause"
QLayout: Adding KToolBar/mainToolBar (child of QVBox/unnamed) to
layout for PlaylistWindow/PlaylistWindow


(no debugging symbols found)
Using host libthread_db library "/lib/tls/i686/cmov/libthread_db.so.1".
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
[Thread debugging using libthread_db enabled]
[New Thread -1232619824 (LWP 8135)]
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
[KCrash handler]
#6  0xb669ea3b in KAudioManagerPlay::KAudioManagerPlay ()
   from /usr/lib/libartskde.so.1
#7  0xb675bd03 in KNotify::restartedArtsd () from /usr/lib/kde3/knotify.so
#8  0xb675c01d in KNotify::KNotify () from /usr/lib/kde3/knotify.so
#9  0xb675c85a in kdemain () from /usr/lib/kde3/knotify.so
#10 0x0804e6bf in ?? ()
#11 0x00000001 in ?? ()
#12 0x0807e740 in ?? ()
#13 0x00000001 in ?? ()
#14 0x00000000 in ?? ()