I was thinking this was a bug in the new releases 18 and 19rc4 but I found an old log with IMU data that did display.
So the question is: why will these logs, downloaded with 19rc4 not display the IMU data in the graphs.
Screen shot of the display and log attached.
Mission Planner will display the graphs as expected.
Mac OS X 10.11.2 Mac Pro (late 2013)
[attachment=0]Screen Shot 2016-01-05 at 11.27.48 AM.png[/attachment]