Earlier you said your browser hung on that URL. Since your browser has a direct connection with Amazon, there's nothing we can see or do. What exactly do you see when uploading? Are there any errors that show up in your browser's web inspector (timeouts and such)? Or maybe things do work, but very slowly? Can you check for network activity while the browser seemingly hangs?
I cannot reproduce this problem. I was able to upload a file to your repo just fine.
I can also see that you have uploaded many files in the past, one as recent as yesterday.
Any chance you could swap computers and/or locations to give this another try? I cannot explain what you are seeing in Chrome there. It seems to claim it is still receiving data, even though it already has the 304 status code printed (which by definition means the request has ended).
I am facing the same problem most often; I am trying to upload a 42Mbytes executable jar, after uploading 20 to 25% I get "The connection to bbuseruploads.s3.amazonaws.com was interrupted." , Error code: ERR_CONNECTION_RESET