for me cairo 1.12.0 introduced the same rendering issue in gtk2 apps but it broke the fade effect from gdm after login, now being black.
xorg-server 1.12.0.901 xf86-video-nouveau 0.0.16_git20120210-1 mesa 8.0.2-1 cairo 1.12.0-1 with xcb enabled
for me cairo 1.12.0 introduced the same rendering issue in gtk2 apps but it broke the fade effect from gdm after login, now being black.
xorg-server 1.12.0.901 git20120210- 1
xf86-video-nouveau 0.0.16_
mesa 8.0.2-1
cairo 1.12.0-1 with xcb enabled