Without more info it's hard to say what is happening.
Does this message appear as soon as amarok runs, or only when you try to do something in particular?
Do other sound / multimedia programs work for you? (Examples: kaffeine, xine, mplayer.)
Did you install amarok from the fedora repositories, or is this a version from somewhere else?
Could you try running amarok, then when you get the crash, type
Code:
tail ~/.xsession-errors
in a konsole to see if there is any info on what caused the crash.