Thanks. Well, it is a mystery.
I'd like for you to turn on some additional logging in Photo Mechanic. In order to turn the logging on, you'll need to create a file named PMDebug.txt and you have to place it among Photo Mechanic's preferences files. Photo Mechanic's preferences files are stored in the following location:
<your home folder>\AppData\Roaming\Camera Bits, Inc\Photo Mechanic\
Create the PMDebug.txt with your favorite text editor (it must be plain text and not some RTF or Word document.) It needs to have the following contents:
STARTUP_LOGGING ON
Save the PMDebug.txt file to the above folder. Then run Photo Mechanic Plus and reproduce the problem. Next, go to the Help menu and choose the 'Reveal Support Data...' menu item. Your PM.log file should now be compressed and a Windows Explorer window should come forward and show you the file. Please add it to your reply to this message.
Thanks,
-Kirk