upgrade to xorg 7.2 => xmga driver broken

Hello,

Since I upgraded my xorg installation to 7.2, a nasty bug has appeared. 
When I move or resize a running xmga mplayer window, a green rectangle 
replace the image. Sometimes when i move again the window, the complete 
or incomplete image comes back.

mga_vid_test works fine.
The xv driver works fine.

Before :
Module mga: vendor="X.Org Foundation"
compiled for 6.9.0, module version = 1.2.1
Module class: X.Org Video Driver
ABI class: X.Org Video Driver, version 0.8

Now :
Module mga: vendor="X.Org Foundation"
compiled for 7.2.0, module version = 1.4.6
Module class: X.Org Video Driver
ABI class: X.Org Video Driver, version 1.1

I have looked for this bug in xorg bugzilla without success.

Anybody can help me ?

Thank you