I do not use plugins to play my video files. Instead, I rely on the media player itself. Currently there are many files that open in either VLC or Windows Media Player when I click on their link in Firefox. Some other file types do not open immediately and I am prompted with a box asking me to choose a program to run the file. I click on "Do this from now on" or whatever it says, hoping that when I open a similar file type, I would not be prompted with this message again. Unfortunately this is not the case. While many files open my media players directly, there are many that still ask me what program to use..even though it is checked to use a specific program.