This is noticeable the most when you set desktop to have black
Then you can see thin Technicolor lines at several Y position starting
the left of side of the screen and kind of "shooting" (i.e. moving
fast) to right side of the screen. The Y positions and line length and
color change all the time at relatively high frequency.

My setup:
P4 2.6 MHz - 1GB Ram
Radeon 9800 Pro 128 MB
Suse 9.1 (updated with all available updates from suse)
ATI Driver 3.14.1
XFree86 4.3.99

Does anyone know how to fix this?
Does anyone have same/similar setup working correctly, could you
send my your XF86Config file.