Monitor Screen Keeps Shaking

[Soo-Hyun Choi]

Hi,

I've got a machine for dual boot with WinXP and Ubuntu Hoary 5.04. If
I boot with WinXP, the screen just works perfect. My monitor is
Philips 170S (LCD screen), and VGA card is Radeon 7000 series.

But if I boot with Ubuntu, the screen is keeping shaking and it's very
unstable. (i.e., the screen is keeping tiny trembling and flickering.)

Because the screen just works perfect under WindowsXP with same screen
resolution, I don't think the problem is in the LCD monitor or the
graphic card.

Did anyone have similar problem like me? and got any idea to sort this out?

Thank you.