Odd problem I noticed last night. On my Mac Pro, I have several mp4, wav and mp3 files on my desktop. When I mouse over (unopened) icons, I get the usual "play" symbol to appear and I can preview the music file without opening it. HOWEVER, on my MacBook Pro, I try the exact same thing and...no preview, no "play" symbol, nothing. Both machines are running 10.6.2, newer machines, etc. All up to date. Not a big problem, but...HELP! Thanks.