You've got an extra set of image tags there. Also, you don't need the URL tag, just the URL itself.
Instead of [URL][img] and then the link, you just need [IMG]myimagelink.com followed by the close image tag which has the forward slash in it [/EyeMG]
Of course, so that it it will display as text, I had to drop the http:// stuff for the link and couldn't properly show the close tag, which looks like this