I have just discovered exactly the same prblem on my Samsung X460.
It's just over a year old and the screen is flickering just as you described.
Did you manage to get it fixed?
This morning when I first turned on my laptop I noticed something strange. It's hard to describe but in the upper-middle part of the screen, there are clusters of "flickering pixels". It looks a little like static. The pixels themselves seem cyan but it is only evident when this part of the screen is light shades of cyan/teal/green/grey. It's most evident on the Vista startup screen!
I have not made any changes lately and the laptop has not left my desk in a few weeks. It's only about a year and a half old. So this seem to have come out of the blue, with no cause I can identify.
I've tried rebooting, restore point, updating the video drivers, the system diagnostic, the basic system restore. Nothing has made a difference. I phoned Samsung and their only suggestion (short of sending it in) was to do a complete system restore. I'm just looking for other suggestions before I take either drastic step. Thanks in advance!