I'm pretty sure now that this relates to the Intel driver. I tried adding 'Driver "vesa"' to my xorg.conf:
Section "Device"
Identifier "Configured Video Device"
+ Driver "vesa"
EndSection
and restarting X. This fixes the problem, although I'm not sure how to confirm that I'm really using VESA (Xv video overlay is unavailable, so I guess that's a good sign).
I'm pretty sure now that this relates to the Intel driver. I tried adding 'Driver "vesa"' to my xorg.conf:
Section "Device"
Identifier "Configured Video Device"
+ Driver "vesa"
EndSection
and restarting X. This fixes the problem, although I'm not sure how to confirm that I'm really using VESA (Xv video overlay is unavailable, so I guess that's a good sign).