g-p-m takes several minutes to start up, and causes X server to have high CPU usage whilst doing so

Binary package hint: gnome-power-manager

I originally reported this as part of bug 307306, but it looks like it may be a separate issue.

On g-p-m startup, Xorg has high CPU usage for about 2 and a half minutes.

In order to debug, I turned off autostart of g-p-m in gnome-session-properties and instead ran it manually as 'gnome-power-manager --no-daemon --verbose' so that I could capture its logging. I am attaching the result. Of particular relevance, note that in the logs there is a gap of 2 minutes 26 seconds in the log timestamps at line 86 of the file - it is during this interval that the CPU usage is occurring. If the log output is anything to judge by, it looks like g-p-m may be blocked waiting on Xorg during this time. Once this situation unblocks, a HUGE quantity of various gpm_brightness_xrandr_* calls are logged.

http://launchpadlibrarian.net/21698068/gnome-power-manager.log