Today i tried the 8.0.0 kernel 4.8.13 with mb.. still conituity counter errors. The build without media_build works fine for me. 
This is odd. Probably some media_build driver issue, unrelated to the issue I described in my original post.
On my RPi3 + DVBSky s960 I tested the following:
Official build - 8.0.0 with media_build, kernel 4.9.8 - problematic (as described in original post). Advanced deinterlacing causing video corruption.
8.0.0 without media_build, kernel 4.9.8 - problematic (as described in original post). Advanced deinterlacing causing video corruption.
8.0.0 with media_build, kernel 4.8.13 - no issues. Can use Advanced deinterlacing, no video corruption.
8.0.0 without media_build, kernel 4.8.13 - no issues. Can use Advanced deinterlacing, no video corruption.