Hi again...
This is AVCHD correct directory structure. I have created it with HD Writer, using single sequence recorded with Panasonic camera.
\AVCHDTN\
\AVCHDTN\thumbnail.tdt2
\AVCHDTN\thumbnail.tidx
\BDMV\
\BDMV\index.bdmv
\BDMV\MovieObject.bdmv
\BDMV\BACKUP\
\BDMV\BACKUP\index.bdmv
\BDMV\BACKUP\MovieObject.bdmv
\BDMV\BACKUP\CLIPINF\
\BDMV\BACKUP\CLIPINF\00000.clpi
\BDMV\BACKUP\PLAYLIST\
\BDMV\BACKUP\PLAYLIST\00000.mpls
\BDMV\CLIPINF\
\BDMV\CLIPINF\00000.clpi
\BDMV\PLAYLIST\
\BDMV\PLAYLIST\00000.mpls
\BDMV\STREAM\
\BDMV\STREAM\00000.m2ts
\BDMV\index.bdmv
\BDMV\index.bdmv
\BDMV\index.bdmv
\IISVPL\
\IISVPL\00000.vpls
So there is no CERTIFICATE folder. In the case of PowerDVD 8 the folder makes disc unplayable.