I just tested this and it is working for me. We've also had 10 people successfully submit 70 photos so far, so it's working for some. Let's see if we can figure out what is happening here.
Are you uploading a photo from your hard drive?
What steps are you taking to enter it? Do you click on the "Choose File" button, locate the image, then click the upload button? Or are you using the BB Code option?