Comment 7 for bug 261724

It looks like it is receiving an awful lot (many thousands) of brightness key events for a single press.

As for the strangeness on plugging/unplugging:
TI:13:36:43 TH:0x8d80640 FI:gpm-brightness-xrandr.c FN:gpm_brightness_xrandr_foreach_screen,414
 - using resource 0x8e0e718
TI:13:36:43 TH:0x8d80640 FI:gpm-brightness-xrandr.c FN:gpm_brightness_xrandr_foreach_resource,375
 - resource 1 of 3
TI:13:36:43 TH:0x8d80640 FI:gpm-brightness-xrandr.c FN:gpm_brightness_xrandr_foreach_resource,375
 - resource 2 of 3
TI:13:36:43 TH:0x8d80640 FI:gpm-brightness-xrandr.c FN:gpm_brightness_xrandr_output_set,322
 - percent=50, absolute=7563
TI:13:36:43 TH:0x8d80640 FI:gpm-brightness-xrandr.c FN:gpm_brightness_xrandr_output_set,324
 - hard value=15125, min=0, max=15125

[predictable ~42.5 second hang]

TI:13:37:26 TH:0x8d80640 FI:gpm-brightness-xrandr.c FN:gpm_brightness_xrandr_foreach_resource,375
 - resource 3 of 3
TI:13:37:26 TH:0x8d80640 FI:gpm-backlight.c FN:gpm_backlight_brightness_evaluate_and_set,456
 - emitting brightness-changed : 50
TI:13:37:26 TH:0x8d80640 FI:gpm-profile.c FN:ac_adaptor_changed_cb,635
 - on battery
TI:13:37:26 TH:0x8d80640 FI:gpm-info.c FN:gpm_info_event_log,579
 - Adding 1 to the event log