I had a handfull of jpegs to upload to zenfolio from a vast folder of jpegs. Some just wouldn't work. I think I've worked out why so i thought I'd share this.
Some of the files had no filetype suffix, when PM got to one of these the copy dialog that comes up before the images are queued to upload would stop before the progress bar was full. No error was displayed. No uploads started.
i checked out the files and added the .jpg suffix, now it all works as it should.
hope this helps