Keep getting flickering footage on 5D Mark III

[MortenSJ]

Hi guys

This has really become a problem for me! I shot from the back of a car the other day, and a lot of the footage has some black flickering going on. It's quite subtle but its very noticeable. Is something wrong with my camera? I have experienced this before. Could it be the vibrations from the car? I shot from a dolly which was hard mounted to the car. I used an ND filter, could that be the problem?

Workflow is RawMagic to Davinci.

[imageus]

Are you sure you don't have the HDR option turned on? HDR video will show flickering - one for high iso and one for low.