I am running Photo Mechanic 4.5.2 Beta 0628 on Windows.
I have noticed if I leave PM minimized for a little while, when it is restored the Navigator panel repositions itself. I had the Favorites panel docked at the top left of the workspace and the Navigator panel below it prior to minimizing PM. On a restore, the Navigator panel is now to the right of the Favorites panel. Futher, the Navigator panel at first seems to refuse to allow me to reposition it. After attempting to reposition the Favorites panel I can then reposition the Navigator panel.
This only seems to happen if PM is left minimized for some time. This problem did not seem to occur with ver 4.5.1.1.
-Ian