Emacs 24.4.50.1 on OSX - problem with emacs locking disk images

[PLK]

I have been using Emacs 24 on OSX for a long time but I noticed in recent 
months, I think with an emacs update (I build from source out of the Git repo), 
that if I mount a disk image, edit a file on the disk image in Emacs and then 
close it, the disk image refuses to eject, saying a file is still in use. I 
have to quite emacs to be able to eject the disk image. This was not the case 
with Emacs 23 or earlier releases of 24 as I remember.

Has anyone else seen this or know of a fix?

PK