Song book number input box - not clearing and unexpected 'Enter' action

[Richard Graham]

I assume this is something overlooked from the inclusion of a song being put into multiple song books. A couple of minor issues (put together as it's probably the same thing really):

 - Pressing the 'Enter' key after typing the number within a book doesn't add the book instance to the song, but closes the window, using the 'Save' [Song] button (so any info is saved).

- On re-entering the song edit box (on any song), if a number was inserted into the box and the window exited as outlined above, that number remains in that input box.

OLP 2.3.2; Windows 8.1 and OSX El Capitan.