Mac OS X Version 10.5.6 I am running normal operations but lately my MacBook has been acting up. Even if I quit all of my apps 50% of the CPU is being used by the user and my fans are running faster too. Before, I could run the apps I used daily the fans stay from 1995 to 2005 RPM. Now I still use my daily apps and the fans are running at 2500+ RPM and it gets higher and higher. I haven't noticed any sluginess but I don't know what is causing it. Applications that I would use daily are Safari, Adium, and Twitterrific. That's it.