Thanks.
Sam, the OS X "Quit" menu problem didn't show up today, though the conditions were similar to before. Just wondering if it was fixed, or if I should continue trying to repeat it.

a few Library notes:
--I assume DnDing a file from one Library folder to another isn't enabled, and that command-clicking a file among a selection still deselects all the others instead of the expected file. (just checking).

--it would be good if the virtual media folders were also created in the OS. That would make the Explore button more functional.

--I REALLY like the fact that individual files can be shared or unshared without losing all the hits/locations data.

--adding a Shared/Unshared column to the Library would help check which files need to be added. A "Date Modified" (or Added) column, as in iTunes or Finder windows would also be useful.

--when sharing a group of unshared files, any already shared files among the selection end up with all their hits/locations data reset. Would be nice if already shared files were ignored in this minor case.

-the duplicate files handling on the Search pane is a very welcome addition. The dialog L&F is relatively cluttered on OSX, and perhaps default settings could be optimized with automatic defaults.