Image/icon artifacting with GNOME2 and Xinerama

[Ryan Boren <rboren fuzzybelly org>]

I've tried G2D B2 and G2D B3 (via GARNOME 0.8.0 and 0.8.5) and have
experienced problems with icons not displaying, displaying only when
moused over, displaying with white lines and other artifacts running
through them, and displaying randomly upon the desktop.  Nautilus is
particularly bad.  Nautilus windows often come up with no icons visible.
 Text is visible, but there is empty space above the text where the icon
should be.  If I scroll the window, the icons will appear, albeit all
piled up in one corner of the desktop rather than in the window where
they belong.

Rubberbanding causes artifacting all across the background if an image
is used as a background.  If a solid color or gradient is used, no
artifacting occurs.

All GTK2/GNOME2 applications have similar problems regarding image/icon
display.

I'm running a dual head xinerama setup using a Matrox G450.  Typically,
the desktop is better behaved on the right head than on the left.  Image
display and rubberbanding are much better on the right head.  If I turn
off xinerama, restart X, and relaunch GNOME2, everything behaves much
better other than Nautilus refusing to post windows.  The refusal to
post windows may be because I turned off xinerama but did not rearrange
the screen layout in XF86Config-4.  Nautilus may be trying to post to
the unmanaged right head.  I'll retest later with a proper single head
config.

Anyway, is anyone else running xinerama and experiencing these problems?

/ryan