Jayden,
you must go to the photo in flickr, click "all sizes" and then use the url there.
eg for one of my photo's;
http://www.flickr.com/photos/3260136...7622727325571/
then choose the size, and down the bottom it says
"2. Grab the photo's URL:"
In that box is what you must use.
so if i do that here,
it works fine!