John, this is a good piece of detective work. I can confirm your findings. It happens for me only if I generate, after having viewed in Staff Roll Notation Mode.

I suspect you have found an 'undesirable / unintended' operation.

Here are my findings:

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2014-01-29_00-01-22.jpg (66.99 KB, 37 downloads)
2014-01-28_23-59-12.jpg (68.86 KB, 37 downloads)
2014-01-29_00-02-10.jpg (103.61 KB, 37 downloads)
2014-01-29_00-03-01.jpg (87.44 KB, 37 downloads)
2014-01-29_00-03-48.jpg (91.42 KB, 37 downloads)

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