I know there are a lot of questions about this -- I've read at least 100 questions about it but still can't find a solution to the Nvidia screen flicker issue. I've had this issue since 11.10. The screen jitters and flickers about every 3-5 seconds. I'm running Ubuntu 12.04 LTS on a Gateway GT5028 with the Nvidia 6100. Any solution would be appreciated. I'd like to see this issue resolved for me.
I had the same problem. You are confused because cogitoergosum assumed that you understand how the command line works. You will need to open a command prompt, and you will need to learn how to use several commands. The only way to truly solve this problem requires working on the command line interface (CLI). CLI skills are extremely valuable, especially in professional computing; so I will help you get started.
I found the solution to Nvidia bugs on Linux here for 64 bit: Nvidia & Linux x64 - common problems and solutions Readme - Here's the same readme for 32 bit (x86): Nvidia & Linux x86 - common problems and solutions Readme - 256.44 If you are using different Nvidia drivers for Linux, then you can find similar readme files on the Nvidia site here: Linux Display Driver Archive.
If you really want to increase your skills, you should Google the linux documents on shell scripting.
Try turning dithering off (disabled) using nvidia-settings. If the problem is resolved, update /etc/X11/xorg.conf to add (Option "FlatPanelProperties" "Dithering=Disabled") to the Screen section. Good luck.