What URL are you using? There's a specific one for each image, which you obtain by using the link provided with the image to copy to the clipboard (or if that doesn't behave with your browser, simply writing down the URL that presents itself on your screen when you place your cursor over that link, and typing it into the sig block set up with the
tags around it.) Each of these URL's will be exactly the same, except for the file name of the image in question.
Edit: I see Village Photos has changed the account structure while I wasn't looking! Poop! Oh well, I think a Plan X will continue to cover my needs, and $5 for 6 months is pretty nominal. Obviously the above comments are specific to Village Photos, but I think the process won't be much different no matter where you go -- you'll still need a URL to put between those tags, and it will be specific to your image.