Nagios 3: application/wav ?

For some reason, the Nagios developers have changed the mime-type of the background sounds from application/x-mplayer2 into application/wav in Nagios 3. In Firefox, this results in an popup "Additional plugins are required to display all media on this page". Badly enough, the plugin finder doesn't find any working plugin, while it's just a simple WAV that should be played.

I just patched both CGI's to get our beeps back, but I wonder why the mime-type was changed, as the old application/x-mplayer2 works fine in Firefox and IE. Any mime-type specialists around?

(This issue was also mentioned by other people on the nagios-users list)