They still haven't fixed all the flickering GUI issues in Yosemite. The overall graphics issues in Yosemite is pathetic. As a matter of fact, I installed Mavericks on my Mac Pro last night and all the flickering GUI problems went to away. When I say "flickering" GUI I mean you can see flashing of the graphical user interface when using some applications. It happens a TON in Apple's very own Logic as a matter of fact. I even made a video of it happening (hoping it would help). No such luck...
See video:
https://youtu.be/y_G0Q8J2Egw?list=UU...ldpev3ffm2okjA
See video:
https://youtu.be/y_G0Q8J2Egw?list=UU...ldpev3ffm2okjA