Although we were initially suspicious of a hardware problem, performing a safe boot (boot with shift-key down) eliminates the problem. Further investigations revealed that the problem only occurs when Quartz Extreme is enabled (via System Profiler). Quartz Debug (/Developer/Applications/Performance Tools) can be used to manually enable/disable Quartz Extreme. | Although we were initially suspicious of a hardware problem, performing a safe boot (boot with shift-key down) eliminates the problem. Further investigations revealed that the problem only occurs when Quartz Extreme is enabled (via System Profiler). Quartz Debug (/Developer/Applications/Performance Tools) can be used to manually enable/disable Quartz Extreme. |