Laptop fan moves/squeaks when shutdown

[Kurtismonger]

I have a Toshiba Satellite laptop which is actually running fine. However, when it's shut completely down it makes a tiny squeaking sound every couple of minutes and the fan twitches. When the laptop is running it does not make the sound and the fan operates as it should. If I unplug it and remove the battery the sound does not occur. As soon as I put the battery back in or plug in the AC adapter the sound/fan twitch will continue to occur.

[Kurtismonger]

I should add that the fan doesn't always twitch in concert with the sound and the sound doesn't seem to be coming from the fan.