Thanks for responding
Someone responded here http://wordpress.org/support/topic/error-when-sideloading
About altering a line if code
Do you know how can you explain where to do this - any help is appreciated thanks
I ran into this problem as well, and for me it was a problem with having spaces in the URL I was trying to get (it looks like you probably have the same problem).
There is an open ticket about this:
As a desperate quick fix, I wound up changing my wp-admin/includes/file.php to change spaces into "%20"s -- though changing core files is a really bad idea! (I needed a solution Right Now, and I will be keeping track of the changes, as well as the ticket to see if it gets resolved.)