I note with my NiMh-powered Nikon D1h that if the battery indicator reads half-full and I turn the camera off and on again it often reads full. I doubt any appreciable charge is added to the battery by doing this. With the D1H, however, having the camera in "full battery" mode keeps it from shutting all the displays off the second your finger leaves the shutter button, so the illusory full battery indication is worth something. It probably accounts for the fact that a D1h can go from half-full to dead battery in a heartbeat if it's been turned on and off a lot.
So, I might suggest that your *istD is doing the same thing--the battery is actually very low but the battery level indicator isn't correctly reflecting that fact. DJE
