When the Audio is Dolby True HD it's fine, the MKV works perfectly as usual

When the Audio is DD+ there is no audio in the MKV.
I've Demuxed the EVO from the HDDVD disc using EVOdemuxer then recombined and created a Bluray ISO using TSmuxer.
Then I've mounted the ISO and played the disc using MPC-HC.... The DD+ plus stream is playing and I have audio again - however it's not in sync with the video.
I've then created an MKV from this "bluray iso" and then audio is gone again!!
This happens on every HDDVD disc I own that has DD+ plus on it.
Anyone any ideas about this, a bug?
thanks