I just completed a major upgrade to a Haswell i7 on a GA-H87-D3H motherboard. Can't afford a new graphics card so I'm using my old GTS250. It works perfectly EXCEPT for Viewer mode in Aperture. Photoshop and Lightroom are fine, as is thumbnail views in Aperture, but when I switch to full screen Viewer mode I get a highly distorted image. Look at attachment. I've tried creating a new library and importing new images but nothing changes. Any help gratefully received!
Addendum: I just noticed that I get the same type of image in the map window of Apple's new Maps app.
See the attachment for a screen shot.