Strange image effect & modesetting support for HD4250?

[Grant]

When I was using an Nvidia video card, I noticed a strange sort of
fuzzy edge effect if I used nvidia-drivers.  xf86-video-nouveau didn't
have the same problem.  Now I've switched to an ATI video card and
unfortunately I have the same problem with xf86-video-ati.  Does
anyone know how to fix this?

I tried to enable the new modesetting radeon driver in the kernel to
see if that would help but it doesn't work with my HD4250 card yet.
Would the new modesetting driver help, and if so, when might it be
compatible with the HD4250?

Here's a photo of the effect around the mouse cursor:

http://imageshack.us/photo/my-images/804/cursor.jpg

- Grant