0plus1 : I know that the loadURL (which isn't mine) plugin has a once where he doesn't update the graphical view when it fetches an image, but some time after...
If you want to use my behavior, you can load images from the exported image folder. Or you can place directly your own imagefiles in a folder next to it.
If you use a global var "image_to_load", and you exported the game "MyGame", say, to dropbox, you need to fill your var like this :
image_to_load = 'http://dl.dropbox.com/u/YOURADRESS/MyGame/images/' & 'name_of_your_image.png'
You can then pass 'image_to_load' as the adress to my behavior.