see http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=252281
BTW. text/x-lyx appears to be also how they are classified by the old gnome-vfs-mime-magic file.
Actually, it looks more logical to me to mark it as a sub-class of text/plain, following the case for application/rtf.
Thanks, fixed by making "text/x-lyx" an alias for "application/x-lyx" and "application/x-lyx" a subclass of "text/plain".
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