Khendar,
How long do you think it will take to find the solution? My husband is a web developer and he could find a solution in three hours. For a problem unsolved for more than 15 days, I think you are not willing to solve it.
I think this situation is very bad for you and for all the artists, since you simply appropriate the images of thousand of people without paying for it, and taking away all the rights that the artists should have over their images.
Quoting the “Submission Terms” from your challenges:
"You retain all of your ownership rights, including but not limited to Copyright, in your User Submissions. However, by submitting the User Submissions to CGSociety Services, you expressly acknowledge and agree that you grant Ballistic Media worldwide, nonexclusive, perpetual, royalty-free, irrevocable and transferable license to use, reproduce, distribute, prepare derivative works of, display, and perform the User Submissions in connection with the CGSociety, Ballistic Publishing and Ballistic Media (and its successor’s) business. The foregoing license granted by you terminates once you remove or delete a User Submission from the CGSociety Website."
Although I find the bold part abusive, it shoud be “terminated since the images are deleted”. But if removing the images is impossible… What can we do?