missing files and growl notifications

Hello,

i'd like to report a bug about missing files in the playlist.
I've attached an USB drive and i've added about 1000 files. I've closed cog, removed the usb drive and and reopened cog.
Clicking on a missing file i get a enormous amount of grow notifications that hangs it for few minutes.

i think it's better to notify only if the file exist, avoiding crashes and freezes.

Thank you,
Eduard