After poking at this bug for a while, I discovered that the system isn't actually locked, or at least you can unlock it easily.
You can "unlock" PhotoScan by clicking on the Model tab. Clicking back on the photo will display it. Of course, this is a gruesome workaround and makes a very long workflow even longer.
To pan and zoom, I have to go to full-screen mode.
P.S. Coming back from Fullscreen view is an adventure and is presumably a different bug (but could be related.
-Leland
Setting the shortcut to use the --opengl angle switch appears to have done the trick. I can only have one photo tab open at a time, but maybe that's the standard behavior. Haven't checked yet to see if returning from Fullscreen is wonky.
You have to add the --opengl angle switch to the TARGET field in the shortcut properties box. Adding it to the 'Start in' field does nothing.
Go to where your PhotoScan EXE file is (probably c:\Program Files\Agisoft\PhotoScan), right-click photoscan.exe and select 'Create shortcut'. After you add the ANGLE switch, you can drop the shortcut into your Start Menu (C:\ProgramData\Microsoft\Windows\Start Menu\Programs).