#6. "RE: Intermittent black on image D3100" In response to Reply # 4
Check the Exif data of the dark image and compare the settings (Shutter Speed, Aperture (f/#), and ISO) to the settings of the image both before and after the dark image. If the difference in the settings is large, I would suspect a problem with the meter. If the settings are similar I would suspect an issue with the shutter.