While it may be nice for some people to have g-p-m provide a battery discharging graph, personally I think this is a bug because this behavior prevents the hard drive from spinning down and thus shortens battery life and may lead to early hard drive failure.
I can confirm that, on my system, about every 90 seconds gnome-power-manager is writing to the file:
$/HOME/ .gnome2/ gnome-power- manager/ profile- G71C0001W210- 38880-000000019 3-discharging. csv
While it may be nice for some people to have g-p-m provide a battery discharging graph, personally I think this is a bug because this behavior prevents the hard drive from spinning down and thus shortens battery life and may lead to early hard drive failure.