You can clearly see you've not created it. If anything we can ask for copyright. If you want i can show like that each of your themes in the topic! So stop complaining about others and stop thinking only you can create everything and others can't do absolutely nothing but copying you. I hope after this all your doubts are cleared up. Thanks!
Update: We did a major rewrite of the code behind Upload Wallpaper and Upload Theme yesterday, and unfortunately a few bugs in Upload Theme sneaked by us. I've fixed those bugs now and you should be able to upload themes again. Otherwise please give feedback with exact error messages you see on your screen. -- bigbluechief Zedge Admin