First off my setup:
Ubuntu 14.04 with AMD HD7700/ intel3000 GPUs.
Laptop: hp Envy15
I am having an issue where the virtual desktop space appears to be scrambled/ overlaps on my monitors making GUI use impossible. The screen also blinks showing the desktop space above and below when moving the cursor. This only occurs when I plug in my second monitor to the HDMI port on my laptop, and the laptop is setup to run the High-performance GPU. When running the intel GPU the screens are fine. I have tried doing a purge and fresh install of the lastest driver but am still having the issue. I used the recommended installation procedures in the wiki docs. I tried adjusting all the settings in the ubuntu display menu and nothing seemed to fix the issue. Refer to the links to see what my screens look like.