I have not had that happen yet, but this is weird. I just did a playlist that has a mix of sample/bit rates and as long as I let the songs end and Amarra automatically switches to the next track it is fine. Then, I tried going from 96 to 44 in the middle of a song and the reaction is a slow-mo artifact I guess from the 96K song and then the 44K song starts playing fine. I did it with a number of different tracks and the same result occurred. Same result with 176 or 192 files.
After a number of back and forth switches in mid-song, Amarra and or the Model 4 locked up, a couple of times. I am not sure how to describe all of these things, but there were some digital clicks and artifacts in between tracks. None of this stuff has happened to me just playing things straight through.
Amarra is not opening when I open iTunes although iTunes will open when I open Amarra. Odd. I also have to Force Quit Amarra too often when Quitting the program. These quirks and bugs are getting annoying.