With SVGA server and Matrox G400 card, in 1024x768x24 mode, there is a blue
vertical line on the bottom third of the screen about a third of the way in
from the left.
I haven't played with XF86Config options yet to see what makes it go away.
This doesn't happen with 1024x768x16
24 bit mode is often hosed. Use 32 bit mode or 16 bit mode.