Hello, So i've had this computer since late 2012 and its a Macbook Pro Retina (13") and with Mavericks on it i've never had any problems, never had it freeze up on me. Since installing Yosemite (on the day it came out) I have since had the computer freeze solid 4 times. It's not whilst doing anything intensive, just basic features. I had safari and mail open, was reading an article, stopped to read a bit when I next went to scroll I could not and had to forcefully reboot. Any ideas / any experiencing the same problems? Regret upgrading.