Persistant mid-screen tear EVERY login until I ALT-TAB... then it runs fine forever?

[WarlockJack]

I have an i7 3770k (4.2 OC), 8gb of ram, asus gtx 670, Corsair Force GT 180gb. Runs on Ultra no problem.

Every time I log into wow, I get one large screen tear across the middle of my screen. It happens EVERY time I start up wow and log in. It will persist from character to character guaranteed for as long as I play.

The odd thing is... if I Alt+Tab out of the game and immediately back in, it's gone. And it stays gone forever unless I completely close WoW and start it back up again.

Its not like Alt Tabbing for 2 seconds every time I start wow is the worst problem in the world (It's taken me a couple years of this to even care), but its WEIRD. I had an MSI GTX 560ti and it did it on that too. Then I got a GIGABYTE 660ti and it DIDN'T do it. Now with this ASUS GTX 670... its back.

Yes all my drivers are up to date. I've also built several similar custom computers for other friends and they DON'T do that.

Anyone have a clue?

[Twoddle]

For some reason the vsync signal is occurring in the middle of a monitor scan cycle as opposed to when the scan reaches the end of the display as it should. How does turning on/off triple buffering affect it or toggling vertical sync in game, or changing the resolution?

[WarlockJack]

For some reason the vsync signal is occurring in the middle of a monitor scan cycle as opposed to when the scan reaches the end of the display as it should. How does turning on/off triple buffering affect it or toggling vertical sync in game, or changing the resolution?

Thank you for the help. Unfortunately making any of those adjustments ALSO makes the issue go away. If I put them back to how they were, the problem still stays gone until I restart WoW. O_o