I had quiet a few problems with uploading my theme also...
You need to zip it as .tar and then zip the .tar in a .gz to make a .tar.gz file which can then be uploaded. Otherwise it wont work and it will just tell you annyoing error messages!
Follow these steps:
"Right-click on the .tar file go to 7-Zip menu and click on option "add to archive" or something like that (should me the 6th option in order), choose GZip archive format and then OK, and now you should have it compressed it like .tar.gz"
You misunderstood me... I was talking about uploading themes to this site :)
Thank you for replying, but my problem is still there after compressing the .tar to a tar.gz... Same error message. I really hope someone can crack this problem. Its a shame that the theme uploading service is to hard for us mortal to figure out ;p
the way I was uploading the themes was just to pack it into a .tar package and then to a .gz (.gz is to decrease the filesize, it works without it ). remember, that your theme folder should contain only the css, images and templates folders! YOU ARE NOT ALLOWED TO PUT ANY OTHER FILES AND FOLDERS THERE