Disable Aero
Messing around with Windows 7 in Vbox and I found a strange work around to get it to work.
1. Open up to a random folder and maximize it.
2. Start the game.
3. When the Unity logo pops up, quickly press and hold ALT, then press TAB to move to the maximized folder. (be sure to get to this folder before it leaves the unity logo)
4. Wait a few seconds until you hear the video tape sound. ALT+TAB back to the game.
I do have aero disabled in these instructions.