evince is not in xfdesktop menu?

[Foxy]

Usually most of the programmes show up in the menu. However, I cannot 
find evince there.

> $ locate evince.desktop
> /usr/share/applications/evince.desktop
> /usr/share/gnome-app-install/evince.desktop
> $ mousepad /usr/share/applications/evince.desktop

> [Desktop Entry]
> Encoding=UTF-8
> Name=Document Viewer
> GenericName=Document Viewer
> Comment=View multipage documents
> TryExec=evince
> Exec=evince
> StartupNotify=true
> Terminal=false
> Type=Application
> Icon=postscript-viewer.png
> NoDisplay=true
> X-GNOME-DocPath=
> X-GNOME-Bugzilla-Bugzilla=GNOME
> X-GNOME-Bugzilla-Product=evince
> X-GNOME-Bugzilla-Component=General
> Categories=GNOME;Application;Graphics;VectorGraphics;Viewer;
> MimeType=application/pdf;application/postscript;application/x-gzpostscript;application/x-dvi;image/vnd.djvu;image/tiff
why it does not show up as Document Viewer?