This upgrade came through today: xserver-xorg-video-intel, version 2:2.4.1-1ubuntu6.
It solves the Pipe-A problem (setting not required in xorg anymore).
I've managed to solve screen corruption with the folowing options (found in some earlier bugreports on this issue):
Option "AccelMethod" "exa"
Option "MigrationHeuristic" "greedy"
Option "ExaNoComposite" "true"
This upgrade came through today: xserver- xorg-video- intel, version 2:2.4.1-1ubuntu6.
It solves the Pipe-A problem (setting not required in xorg anymore).
I've managed to solve screen corruption with the folowing options (found in some earlier bugreports on this issue): stic" "greedy"
Option "AccelMethod" "exa"
Option "MigrationHeuri
Option "ExaNoComposite" "true"