I've had problems with this for several days now and i've visited every topic I could find on it and i've yet to find the solution.
What's happening is that WoW isn't giving me the correct resolution options. It's worth noting that I have 3 monitors, 2 of which are 1440x900 and the middle one which is 1920x1080. I always play on the middle monitor, but it's recently only stated giving me options for 1440x900 at highest resolution
I've tried manually changing the resolution in the config.wtf, but it always just resets to 800x600