How to Fix GNOME 3 Shell Screen Blanking / Monitor Turned Off in Ubuntu 11.10 Oneiric / Linux Mint 12

In my AMD/ATI Radeon-powered HP dv6t Quad Edition notebook, sometimes the screen is blank or the LCD monitor turned off and it cannot turn itself on again.
This did not happen in GNOME 2 / Ubuntu 10.04 Natty / Linux Mint 11, and happens only after I upgraded to GNOME 3 / GNOME Shell / Ubuntu 11.10 Oneiric / Linux Mint 12.
To solve this problem when the screen is blank:

1. Press Ctrl+Alt+F1 (to go to the console).
2. Close the laptop lid.
3. Reopen the laptop lid.
4. You should be able to see the Linux console. Enter your username and password to login.
5. Type:export DISPLAY=:0
   xset dpms force on
   ( Note : if you type "xset q" right after the "export" command, you'll notice that "Monitor is Off", which is both strange and scary )
6. Press Ctrl+F7 to go back to your desktop.
   

Note that you may need to change your Power Settings, so that it will do nothing when the laptop lid is closed.
You may also want to configure your Screen Settings to disable turning off the screen.
I have not yet found a more permanent, properly working solution. So right now the above is a temporary hack that works.
You can learn more about Ubuntu and Linux Mint in Ubuntu Unleashed 2011 Edition: Covering 10.10 and 11.04 (6th Edition) !