No. My mac is 24/7. It is recommended if possible that your computer stays open (except for the screen). Hardware hates to go from no tension (off) to tension (on). After thousands of that repeat cycle, it makes hardware get older faster. One thing to check though is the hard drive: a hard drive always writing/reading stuff gets older faster. P2P can be hard drive killer. But it never hapenned to me yet Also os x loves that computer stays awake: at midnight, os x runs maintenance scripts that clean your computer like when you restart it. If you make your computer sleep at that hour, your computer will get slower over the days. There are os x apps that can do those maintenance scripts whenever you feel. I recommend OnyX available at http://macupdate.com/info.php/id/11582

Ciao

__________________
Liens d'intérêt /Links of interest:
Gnutellaforums en français /The House's rules you have to respect / First search the forum, then create a thread / Free software alternatives! - Logiciels alternatifs gratuits!/