Obrigado pela pronta ajuda,mas como estava de fresco resolvi instalar de novo e.... Descobri que são duas actualizações que me dão cabo disto...
A
xserver-xorg-video-ati com a seguinte descrição :
Versão 1:6.9.0+git20081003.f9826a56-0ubuntu2.1:
* Add 103_dithering_rework.patch: Complete, correct fix for dithering
issues we'd initially worked around in patches 101 and 102. Those
patches also appear to have introduced regressions on certain hardware,
which this rework addresses more elegantly. This patch essentially
includes all of upstream's work up to commit 435cf7da, except that it
drops commit 0975e007 (rename radeon_memory to radeon_legacy_memory)
which is unrelated to the dithering problem.
(Closes LP: #274234, #284346)
E a
xserver-xorg-video-radeoncom a seguinte descrição:
* Add 103_dithering_rework.patch: Complete, correct fix for dithering
issues we'd initially worked around in patches 101 and 102. Those
patches also appear to have introduced regressions on certain hardware,
which this rework addresses more elegantly. This patch essentially
includes all of upstream's work up to commit 435cf7da, except that it
drops commit 0975e007 (rename radeon_memory to radeon_legacy_memory)
which is unrelated to the dithering problem.
(Closes LP: #274234, #284346)