Right now we only support "flv", "mov" and "wmv" files..m4v is coming!

In the meantime, you can only use these file formats. IF you are using one of them and you're still getting the bad file name error, be sure you do not have any spaces in the file name. Go back and check -- many Mac users are accustomed to being able to put spaces in their file names. Eliminate any characters other than letters, just to be safe. If you continue to have problems, please email the webmaster, we monitor that email regularly.