For years I've been running WoW across 2 monitors without issues. I have the main game on the left (WorldFrame) and I use the other screen for mini map, chat windows, quests, etc.
Specifics: 2 monitors, both set to 1680 x 1050, so total screens = 3360 x 1050.
WoW doesn't like that for a custom setting so I set it for 1680 x 525 to keep the correct resolution ratio.
WoW graphics set to 'Windowed'. I open WoW and stretch the screen to 3360 x 1050,
Then I set the WorldFrame to fit the left monitor only. Has worked great until the pre-patch.
Issues: The frames are the correct size but the images in the World Frame are too narrow. Almost as if the the world frame is set to 3360 x 1050 and I'm squeezing it into 1680 x 1050. All the other images (mini-map, etc) are just fine.
Also the mouse isn't lining up with images in my squeezed WorldFrame. Looks like the mouse is working based on the 3360 x 1050 image before I shrink it. Eample: If the mailbox is on the left, I have to move the mouse to about the middle of the screen to 'mouse over' the mailbox.
I'm not a programmer but I have an idea of how to do some things. But if this is fixable, it's way beyond me.