When I created the license for the Amphitheatre addon, I misintepreted the terms of use of one of the images to be synonomous with public domain. The skydome in the arena came from this thread on blenderartists.org, which says that you can do anything with the images. However, it then goes on to say that you can't sell the images, potentially making the license not free enough for the Debian Free Software Guidelines, which my arena is currently tagged as compliant with.
In the original License.txt for the arena, I stated that I was the author of the skydome, which I did for convenience and assumed was legal because I thought the image was in the public domain (I had slightly modified the skydome, scaling it down from from its original size). Earlier today, I tried to upload a second revision of the arena that rectifies the licensing mistake. Unfortunately, stkaddons.net seems to have intepreted the updated archive as a source file, which is now attached to the arena awaiting approval, and which I can't delete. I would appreciate any help in getting the new version of the addon up.
Sorry for any inconvenience this may have caused.