http://en.wikipedia.org/wiki/Fixed-pattern_noise
This is how your sensor looks +3 stops @ 160 ISO. It's got nothing to do with ML except for the fact it's no longer denoised and compressed in camera.

I don't think that's a major problem, why would you ever want to push a nearly black image by 3 stops???
Would be good to get rid of it anyway though!
I see you're shooting at ISO 160, why?
The idea of shooting in multiples of 160 is only relevant for standard compressed video shooting, due to the way intermediate ISOs are processed in camera. Eg 160 is a 1/3 stop pull from ISO 200 sensor data before writing to h264.
The 'real' ISOs of the mk3, as evident from analysis of RAW stills , are:
100, 200, 400, 800, 1600, 3200 and 6400. Maybe also 12800.
Going forward for maximum RAW quality these are the multiples we should be shooting in a think