The newest photoshop has a bug. I repeated the problems 4 times. I have an open document and I minimize the window, and then my computer freezes for a quick second and goes to the login screen, and I loose all the work. I have a Mac Mini Late 2014 3GHz i7 16 GB.
Okay, that makes sense, but it has not happened to me before the CC update. I will look into the OS bugs. I'm running OS X Yosemite - Version 10.10.3. I am running the newest Photoshop CC update that came out a few days ago. Not sure the number.