I tried to add some file on my usb stick to kdenlive and only got the answer that the vide file was not valid.

Now I realized that kdenlive does not understand the media:/ url I picked in the file selection dialog by clicking on storage devices. Quite confusing, as I thought the file format was broken....

I also had the same issue with kdenlive 0.6.0-svn on ubuntu gutsy.

I cannot open files on an usb drive with media:/ (then there is an error like no valid file for kdenlive or so) , i have to go to /media/myusbdrive/ and then everything works fine.

I hope you could fix this soon because its a confusing bug.

holzi