When my W500 is on battery power and idle for 3 minutes the screen will flicker once then when I press a key it will blank briefly again before I can continue using the system.

this drove me crazy for over a year, but I finally found the answer:

Once again (I am a long time thinkpad user) Lenovo has shot their own foot.  

To save battery power the default setting is to adjust the refresh rate to 50Hz after three minutes idle.

If you are a writer, nothing is more irksome than having to wait for your screen to blank everytime you go back to type!

go to:  Control Panel -> Power Options 

Select Power Manager tab then click "Launch Power Manager"

In the "Power Manager" click the "Power Schemes" tab

then press the "edit" button to edit the currently selected scheme (or whichever one you want to remove flicker from)

Press the "Next" button

then click "Lower display refresh rate" under battery settings and select "NEVER"

Ugh.    

All of the Wizards that Lenovo adds for managing desktop schemes, backups, etc. are just buggy.

the bios is buggy too, screen blank on reboot, resolution resizing when switching locations.

All the way around, Lenovo starts with a solid peice of hardware, and proceeds to destroy its robustness, with poorly executed features.

     (Not that you are reading this Lenovo, but there is a lesson in this!)

anyway, I hope this helps some other poor souls out there!

--dan