If you are upgrading to Amarok 2.3 Clear Light and experiencing crashes, weird behaviour in layout, CD can’t be played. Then you can take few bold steps as I suggested below.
Note to self: once there is a major update, wipe clean the previous version completely.
Wipe out your config and application layout and database.
mv .kde/share/apps/amarok/ ~
mv .kde/share/config/amarok* ~
You lose all your playlist, cover arts, etc… but Amarok works amazingly well again. You can try putting the config/database back one by one. Though I don’t bet on that. Wipe config alone will not give you a functional Amarok you have to kill apps/amarok as well, like in my case, layout isn’t remembered and new scanned tracks got weird random tag from random existing track.