Odd Graphical Glitches on Brand New GPU's

So I recently built a rig almost identical to the March $2000 rig, more specifically so the 2 XFX 6950's.

Now Playing games and running 3dmark etc.. all yielded great results. HOWEVER one thing gnaws at me, when starting WoW The login screen gives artifacts, not large screen wide ones, but small ones that are corrected shortly after they appear. They pop in and out of existence for 2-5 seconds, then stop, never to appear again (until the next time I open up WoW) In the game itself I never experience this and everything runs beautifully on all ultra settings.

A similar issue happened in League of Legends, once the match loads and starts up the main screen was glitching/artifacting around the players/nexus for about 5-8 seconds then again...never happened during the rest of the game.

The final issue happens when I am on the desktop with no games active, usually browsing the internet or something else non-intensive. What happens is random tiny discolored squares (color varies) not a huge number but randomly appearing around the screen. Sometimes they would disappear/move if i shake the browser around the screen and eventually go away.

I've tried google for similar situations, however I haven't found much. My primary concern is not so much the actual glitches happening for a short time and going away. But more so that they are an indicator of a more serious issue that will escalate and leave me with a defunct card (or two) after my RMA period is over.

While XFX reportedly has a good warranty I'd still like to hear the communities insight on this. I have not had an ATI Card for a long long time, so I'm not sure if it's an existing issue with ATI cards/drivers/etc... and certain games, or something more malicious.

Thanks in advance.

Edit: Just so people know I have been monitoring the Heat levels and neither of them have reached any sort of significant temperature. Highest I've seen has been in the mid 50's, average in wow etc... is under 40 c.
Also these things have occurred with Crossfire enabled and Not enabled.