Friend Can't use mp3s on her iBook

[Joe]

Her problem: " I got my iBook about 4 months ago. I used to use my 
parents G4 where I would edit movies all the time. I recently imported 
a new film project into iMoive (this will be my first movie created on 
my iBook) and the program won't let me import any music files! I used 
to be able to just import the music from iTunes but it won't let me. 
I've dragged the music files to the desktop and even opend them up in 
quicktime but still I can not import them into iMovie. Is there 
something I am doing wrong or something else I have to do? I never did 
anything different on the G4... and as usual they are all mp3's."

I can't figure this one out...