I posted the same topic on NBR but with no real answers.
That's because the people over there aren't as smart as the people over here.
Most LCD displays are susceptible to this issue. You just have to provide the right situation for the flickering to become visible. See:http://www.lagom.nl/lcd-test/inversion.php#invpattern(do NOT run this test if you suffer from epilepsy, and I'm not joking)
See the "Background" section at the bottom of that page for an explanation. On my W700 w/1920x1200 400nit display, box 4b flickers ever so slightly (or sometimes box 4a instead, depending on its screen position), especially if I look at it through the corner of my eye. The flickering is much more pronounced in the full-screen test, where I also see some flickering of 2b.
The gradient that you link to in your post looks fine on my display, with no noticeable flicker.
So what you may be seeing, if you look at that gradient (or any other image) and see flicker, is an interaction between a dithering pattern and the interleaving pattern of your monitor. The dithering pattern could either be encoded in the image itself (i.e. the pixels in the image file contain dithered values), or else it could be introduced by your video card during the display process.
I just blew up that gradient image in Photoshop so that it filled my screen. Then I thresholded it, slowly changing the threshold from 0 to 255, in steps of 1. I did notice a lot of dithering along the vertical direction in the bottom half of the image. So if you're seeing flickering there, it's probably due to dithering encoded into that image itself. In other words, the flicker is due to the special construction of that image (whether intentional or accidental), just as with the flickering you see at the test page on lagom.nl.
If you instead see flickering in images that don't have dithering encoded into them, then you may be seeing an interaction between the dithering pattern being used by your video card and the interleaving pattern of the monitor. If such flickering becomes too objectionable, then you may have a dithering setting somewhere in your nvidia control panel (or a setting in the device manager for your video card, or in a .conf/.ini file) that lets you change the display card's dithering pattern, hence reducing the flicker.
In any case, seeing the above flickering in images you encounter on a daily basis is probably extremely rare.
W700 T9600 @2.8GHz Vista64
8GBram 2GBTurbo 160GB+320GB @7.2k
17" 1920x1200 QuadroFX 3700M/1GB
Blu-ray UltrabayThinkPad W700 Resources Page