SimpleDLNA keeps generating thumbs for unsupported formats

[archfrog]

I'm not sure this is really a bug or a feature but SimpleDLNA v1.0 tries to generate thumbnails for Windows .wmv files every time it starts. This causes a lot of extraneous processing and a number of warnings in the log. I guess it should record that it has already tried to make a thumb and then simply serve a default (blank?) thumb for such unsupported files.