Hello,
It would be great if during the media upload process - the program checked for the media file type to see if it is allowed FIRST. As it is if you are uploading a large movie (or more than one file) and the file type is not allowed it waits until the end of the entire upload process to complete to inform the user the file is not allowed. It would seem it should check and give an error message first - instead of going all the way through the upload process.
It appears to upload ALL the files selected before the error message as well. Why not have it do a simple check first then, if allowed, do the upload - if not - give an error message.