Submitting images not working

I'm trying to create a form that will allow photos to be submitted. I've submitted a few tests and there's no indication of an error, but there is no image in the e-mail notification, the listing for the submission in the admin area, or in the folder where the image is set to upload to. I set that folder's permissions to 777, in case that was the problem, but it's still not working. Any idea why the images aren't going through?