[afremont]

Can I work my way backwards by installing an older version on top of a newer on i.e. 0821 followed by 0820 etc?

Yes.

Okay, thanks for that. I went back to 0819 and it was okay, no constant frame skipping on 720p. I worked my way forward and 0820 and 0821 are fine, 0822b skips frames constantly and loses audio sync. 0823 did the same thing, so it looks like something in 0822b broke for MMAL, 720p live TV and recordings.

Setup is Mythbuntu back end, HDHomerun for TV tuning, RPi2 front end
OMXPLayer unchecked
MMAL checked
Adjust refresh rate unchecked
Resample Audio

Is there anything else that I can supply that might help? Thanks! I appreciate it. I'm back on 0821 for the time being. I had skipped over that version before.