That last message "Experiencing a network problem" should indicate a loss of internet connection, but if you're typing here on the forum from the same computer then the synther should have noticed and resumed.
As for the previous times when it stuck on uploading the last file or while 'publishing', definitely get your log files to Tony. (Trying to copy and paste them here on the forum will be hard because you can't really fit very much in each message.) You can find his email address by clicking his name.
Also, regarding the whole hanging on the 'Publishing' stage shouldn't be happening, but just FYI, sometimes those synths do get through after a time. I see two public synths on your profile here: http://photosynth.net/UserProfilePage.aspx?user=ms_carousel&content=Synths