Q: Chapter Marker Image Bug in Compressor and/or QuickTime?

I'm exporting a project for a client in various formats, and would like to take advantage of the ability to display a thumbnail image for chapter markers which comes from a different frame than the marker itself.

Compressor permits this, but no matter what I do I'm experiencing a problem where one thumbnail is the wrong image, in fact, a copy of an image from the subsequent chapter.

Workflow:

Export a clean ProRes422HQ movie from my editing software (in this case, Premiere Pro CC).

Create a text file with the chapter points listed as timecode (per Compressor documentation).

Read that file into Compressor.

Go to each chapter marker, select "Image: Frame" from the pull-down menu, then enter the timecode of the frame I want to use as an image thumbnail.

Verify all chapters/images in the Compressor timeline.

Export to QuickTime H264 .MOV.

Play the .MOV in QuickTime (not QuickTime 7, but the newer version which comes bundled with OS X.)

The Problem:

In this case, the chapter labeled "Opening Day" has the same image as the chapter labeled "Getting from There to Here".  This occurs even if I tweak the chapter points or image points a bit, or if I create them in a different order.  The result after output is the same.  This also occurs when I output an MP4 rather than a QuickTime .MOV.  I've made sure that all the thumbnail timecode points don't overlap or go beyond their current chapter or anything odd like that.

Is Compressor somehow getting confused during export?  Or is QuickTime getting confused at the time of playback?  Is there any other tool I can use to peer into the output .MOV file to see how the chapters and thumbnails are organized?

Screen shot of problem ("Opening Day" has wrong thumbnail):

Screen shot of actual image chosen in Compressor timeline:

Screen shot of chapter listing text document: