>Actually, he faced the same problem when setting it to 100.
The D700 (model spoken about in video) does not have an ISO 100. It has LO 1 which is akin to using ISO 100. I believe it's done through post capture bit manipulation (not 100% sure on that).
>Can you please try it too and update us?
I have used Auto-ISO as I described without issue. To make sure I just tried it with P,S,A and M modes and it works. When there is sufficient light the camera selects ISO 100. When there isn't it raises the ISO as needed to maximum set value.
Perhaps it's an issue with the LO settings. Never had a camera that had them so cannot test it.