Youtube Uploading Problem

A while back I was commissioned to make a video for a local housing community which was entering an award scheme, I uploaded the video 13min & 1.18 GB without any problems & made it un-listed then provided a link so that the judges & interested parties could view it. It won the regional comp but not the national one. I was then asked to take it down which I did. Yesterday I was asked to put it up again as they were using it for another comp. I tried unsuccessfully, 3 attempts, to upload it from the machine I normally use for internet access. Each time it suffered a "fatal exception" & failed to load, in fact, according to YouTube they are still being processed. Almost giving up I decided to try to upload from the machine that I had used to edit on, no problem!!! Although the problem of uploading is solved I`m curios as to what caused the failure & also I can`t delete the "un-processed" files from my account, any ideas?

 

Cheers