I bought a XFX Double D FX-787A-CDFC Radeon HD 7870 and set it up using the HDMI, DVI and Mini DisplayPort (using an Apple mDP-to-VGA adapter). I hooked it up, installed the drivers and rebooted. The image came up on the third monitor in a weird resolution. Why did this happen and how can I fix it? I am using Windows 7 Ultimate and the system is completely updated. Side note: When I disconnect the Mini DisplayPort adapter it works fine, however for my work I need 3-4 monitors.