SoUseless

No thanks, I won't trouble you further. Thanks for the help, and I do remember trying to manually change the extension out of habit, but realizing my mistake after the fact and doing it the right way... I guess that didn't help.

Thank you so much. Any idea what might have caused the problem to begin with so that it can be avoided in the future?

Thanks. http://min.us/mveQFGN The PDN http://min.us/mveVanc The PNG

This evening, I spent a few hours working on an image in paint.net, saving periodically along the way as a .pdn. When I was finished, I flattened the image and saved it as a .png. Now, however, neither file will open. The .pdn won't open in paint.net and the .png won't open in anything. Both files are too big to attach. Any help on this would be appreciated, because I really don't want to go through the trouble of making that image again.