Greetings!

I have the same problem, but attributed it to the encoder I used (it omitted the Xing header entirely). I have been meaning to run VBRfix on the files to regenerate the header eventually, but that is a long way off unless I can find a way to bulk repair them on the player itself. Note: clearing the metadata does not help in these instances. The rebuild just takes the missing VBR data and recalculates it incorrectly again.