Flickering squares photoshop

[pude.roos]

Hi!
 
I have a new computer (mac mini late 2012) and a new display (Nec PA272W) and I'm using mac OS X Yosemite, I'm also using a wacom Intuos 4 tablet.
I've recently encountered a problem when I'm using Photoshop CC. When I'm zooming in on an image and using for example the brush tool, it's like two big black squares blinking (one on the left and one on the right), i would say they are about 40x40 px in size. I don't know what the problem could be? Problems with the wacom driver or problems with the graphic card? It's only when I'm in photoshop this problem occurs.
 
/Patrik

[Schewe]

Check your Preferences>Performance setting for your graphics card...try unchecking Use Graphics Processor. Do the problems go away? If so, it's a GPU/driver problem. If not, it's may indeed be the tablet driver...check for updates.

[pude.roos]

I did some digging on the interwebz. It seems that the problem has to do with various video bugs in Yosemite. I found this text on Gizmodo:

"Graphical glitches relating to Photoshop seem to be common, and while a support rep confirms that Adobe and Apple are looking into it, there's nothing in the way of a fix or a workaround just yet. The same is true for many of the other graphics issues that have been reported, from Yosemite not identifying the right graphics card to weird colors and shapes appearing on screen. It looks like you're going to have to wait those ones out."

I read that some users only experienced problems after waking the computer from sleep mode. And in my new tests it works without glitches if i start up the computer and use photoshop straight away. But after the screensaver has been running for a while and i tried again a small black square started flickering from time to time again...