OSX: Menu titles don't "unselect"

If you select a menu option that opens a dialog, and then close the dialog, the menu remains lit. For example, select Actions>Show Action List, then hit "Cancel" when the action list opens and you are left with this: The "Action" menu item shouldn't remain blue. The same thing happens with the extensions menu for sure, and likely other menus as well.

Confirmed here on OSX as well. It's been doing this ever since I started using Reaper, I just for some reason ignored it!

Looks like only the Action menu and Insert->Virtual instrument menus are doing this - or in other words it looks like it happens when a non-modal window accessible via top level menus is being opened.