I would recommend to try also: these points before contacting our Support:
delete modifications if you have any (you may also start game in a "Safe mode", check this with the right edge of "Play" button in WGCenter)
"check and repair" client via WGC >> Game Settings (You may check this topic for details)
delete your preferences.xml file in the game folder and set everything manually again with the next game launch
choose another graphic settings and check the result
And only if nothing works, then I would ask you to create a WGCheck report and send it to our Support in the ticket with some notes.