[MrMagic]

You are right, it's related to the bit depth as can be seen with MediaInfo. As far as I can tell, all DTS HD 7.1 tracks seem to have a bit depth of 24, but with 5.1 tracks some are 16 bit and some are 24 bit.

I haven't seen "fltp" yet when playing DTS HD tracks, so I suppose it's all OK