If you own the Nikon D300 digital SLR, thereâ€™s a firmware update available for you to download. This download is intended to update the A firmware only of the D300, not the B firmware.
Version 1.02 of the firmware fixes a problem with the D300 where vertical bands sometimes appear in images captured at shutter speeds slower than 8 seconds.
Instructions to download and install the firmware update may be found at the Nikon website. Mac users here, Windows users here.