I just got off the phone with an Apple Specialist because of some slowdown in web browsing that seemed to be getting progressively worse. The tech had me go the the primary LIBRARY folder on my mac HD and delete the following folders: 1. CACHE 2. STARTUPITEMS UPITEMS and then go into LIBRARY folder under my user ID and delete the following folder 1. CACHE I then cleaned out the trashcan and restarted the computer. Web browsing is much faster now. He recommended doing this once a month if you do a lot of web browsing. Please note - you may get a warning upon restarting your browser regarding the missing cache folders and you just have the OS 'Fix' the problem ( which is one of the options).