Same problem in Oneiric. Flicker in totem, no flicker in VLC on an H264 - MPEG-4 AVC video.
Using gnome-shell, Release: 11.10 Linux 3.0.0-17-generic #30-Ubuntu SMP Thu Mar 8 17:34:21 UTC 2012 i686 i686 i386 GNU/Linux
Thinkpad R60, Radeon Mobility X1400 OpenGL vendor string: X.Org R300 Project OpenGL renderer string: Gallium 0.4 on ATI RV515 OpenGL version string: 2.1 Mesa 7.11
Same problem in Oneiric.
Flicker in totem, no flicker in VLC on an H264 - MPEG-4 AVC video.
Using gnome-shell,
Release: 11.10
Linux 3.0.0-17-generic #30-Ubuntu SMP Thu Mar 8 17:34:21 UTC 2012 i686 i686 i386 GNU/Linux
Thinkpad R60, Radeon Mobility X1400
OpenGL vendor string: X.Org R300 Project
OpenGL renderer string: Gallium 0.4 on ATI RV515
OpenGL version string: 2.1 Mesa 7.11