The MediaDownloader version displayed in the "Acerca de" menu is incorrect.
The version used is the 0.6.8b, but the window shows it is the 0.6.7b version.
I revised the case and I don't know how the old version got uploaded as the new. (or a In between version with the version number not updated)
I've updated the download in the lastest release and it is fixed now.
The MediaDownloader version displayed in the "Acerca de" menu is incorrect. The version used is the 0.6.8b, but the window shows it is the 0.6.7b version.