Same problem here, with a i855gm:
0000:00:02.0 VGA compatible controller: Intel Corporation 82852/855GM Integrated Graphics Device (rev 02) 0000:00:02.1 Display controller: Intel Corporation 82852/855GM Integrated Graphics Device (rev 02)
Both of the different xvattr-settings from Paul Sladen above fix the bad image quality while playing.
Same problem here, with a i855gm:
0000:00:02.0 VGA compatible controller: Intel Corporation 82852/855GM Integrated Graphics Device (rev 02)
0000:00:02.1 Display controller: Intel Corporation 82852/855GM Integrated Graphics Device (rev 02)
Both of the different xvattr-settings from Paul Sladen above fix the bad image quality while playing.