A plugin message is poping up pretty often, always telling me the same, although the music seem to be playing perfectly: 
"The required software to play this file is not installed. You need to install suitable plugins to play media files. Do you want to search for a plugin that supports the selected file?
The search will also include software which is not officially supported."

I don't understand what that popup means, anyway the music is playing so I just want to discard it.
There are lots of possibilities: the popup shows up only at start, or the user get a "do not repeat that message" checkbox... I'll take any option so that rythmbox plays the music without chatty popups while I'm trying to be productive :)

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