In various situations my screen has a strobe light effect as if there is some overlay window appearing and disappearing that covers parts of the screen. The screen doesn't go completely black, more like a black see-through effect flashes very quickly in flickering, thick, horizontal bands. Attempting to take a screenshot yields a black picture.

Areas this happens:
1. Character select screen. Almost the whole screen flashes.
2. Ark summary windows. Just the summary window flashes.
3. Various Ego NPC discussions. Different parts of the UI has these boxes that flash.

This happens on two of my systems:
1. Desktop PC, Windows 8, i7-2600k, 8 GB RAM, AMD HD 6900, Catalyst versions 13.1, 13.2, 13.3 Beta tried, Norton Internet Security.
2. Laptop PC, Windows 8, i7-720, 6 GB RAM, AMD HD 5870, Catalyst versions 13.1, 13.2, 13.3 Beta tried, Norton Internet Security.

Both computers are virus free, not overheating, all drivers updated, all software updates. I also tried uninstalling ATI drivers completely, removed the CAP patches, and ran Driver Sweeper to remove all AMD files before re-installing fresh drivers. This did not help. Turning off anti-virus does not help.

What's very strange is that my girlfriend has a nearly identical laptop to mine (i7-740 but everything else the same including video card and drivers, but different antivirus) and hers does not do this that we've seen. My laptop does this on the same wireless router as hers so it's not network related.

Since hers works and my two computers don't, I have yet to try wearing a tinfoil hat to see if my brain waves are so awesome they're causing an interference. I may get to that eventually.

Anyone else experience this?