Using version 6.20.1, i saw that PIP wil not work with two hd channels, it immediatally crashes computer; and there´s only sound in the first channel opened in pip mode, the others more are muted. Is that normal or a bug?
Anyway, that version is the better i know. Thanks to the Prog team.

Try change video codec or video render. For example possible your video card not support DXVA for 2 video streams.