mack - 3:58 pm on Dec 11, 2009 (gmt 0)

This may help with further diagnosis. Try running an OS from a live CD. Just a simple linux distro should do.

If your system displays the same issues then it is almost sertaily a hardware issue, if not then it is likely to be somethign installed along with your current bootable OS.

The "jerky" screen issue is quite common if the incorect drivers are installed for your graphics card.

Mack.