Description of Problem:
With XFree86 4.0.3 and a SIS630 graphic chip, the graphic screen is blurry and flickers at any resolution over 640x480, no matter the color depth and refresh rate.
Tried many many modelines and all the chipset-specific options within XF86Config, the problem is always there and identical all over.


How Reproducible:
Every time.

Steps to Reproduce:
1.Simply start up X at a resolution above 640x480 (but it's a lot more evident at 1024x768 than at 800x600).

Actual Results:
The whole screen looks blurry and flickers. Seems like a red "ghost image" is created, shifted by 1 pixel on the left of the "right" screen content.

Expected Results:


Additional Information:
The XFree86 log reports nothing strange.
My hardware is a MITAC 7521 notebook with a SIS630 integrated chipset, the display is a 14 LCD TFT.
Tried with another identical machine, all is the same.
	
Will send XFree86.log and XF86Config on request.