Hello Kirk,
if I want to cancel a running FTP-UPLOAD process while the internet connection is broken, the UPLOAD-window will not close and PM freezes.
I just tried it (cancelling an upload for broken Internet connection) a few days ago. It didn't freeze for me. I clicked cancel then close and the window disappears like expected. PM works since then.
However an option to resume the upload (after reconnect or connection to another Internet service from another site) would be a great help instead of needing from the start and fiding out which files were sent and which weren't.
Also a saveable (maybe also emailable) FTP log would help a lot since I like to send the client an e-mail that I uploaded the images to the FTP.