So I've this weird problem since a few days. Just ignore the yellow Fraps FPS counter and the part on the right, it's about the blocks below the yellow counter:
Here's also a video: flashy blocks - YouTube
I've already done some extensive testing and it seems whenever a Direct3D 9 game starts, I get these blocks.
Doesn't seem to happen with Direct3D 11 nor OpenGL games.
I must have accidentally activated them somehow when I tried to get proper Crossfire running with my HD 5970 (which btw. works).
To me they kind of look like some testing/debugging stuff but for the heck of it, I can't figure out where it comes from.
Note: Fraps has nothing to do with it, the counter of course goes away but the blocks stay. I just happen to take photos with Fraps because I've running it all the time.
I've found at least someone else who was having this problem a few years back: flashing colored boxes in upper left corner - Guru3D.com Forums . However, re-installing the system is not an option :-)
I'm using the latest CCC which is 2015.0728.2244.39078 .
Besides trying to activate Crossfire for my card I didn't do anything else (installed software, etc.); these blocks suddenly popped up then (and afaik Crossfire started working from that point on).