[Fedora-packaging] how to handle mimetype

[Tanguy Eric]

I'm trying to package scidavis http://scidavis.sourceforge.net/ and i
would like the files generated by it (*.sciprj and *.sciprj.gz) will be
associated to scidavis and opened in it when i double-click on their.

So i put a desktop file in /usr/share/applications :
[Desktop Entry]
Encoding=UTF-8
Name=SciDAVis
Comment=Scientific Data Analysis and Visualization
Comment[de]=Visualisierungs- und Datenanalyseprogramm
Comment[fr]=Outil d'analyse scientifique de données
Icon=scidavis
Exec=scidavis %f
Terminal=0
Type=Application
Categories=Science;Graphics;X-Fedora;
MimeType=application/x-scidavis
X-Desktop-File-Install-Version=0.13

and a xml file in /usr/share/mime/packages : 
<?xml version="1.0" encoding="UTF-8"?>
<mime-info
xmlns="http://www.freedesktop.org/standards/shared-mime-info">
  <mime-type type="application/x-scidavis">
    <comment>Scidavis project</comment>
    <glob pattern="*.sciprj"/>
  </mime-type>

  <mime-type type="application/x-scidavis">
    <comment>Scidavis project</comment>
    <glob pattern="*.sciprj.gz"/>
  </mime-type>
</mime-info>

after this i run
update-mime-database /usr/share/mime
update-desktop-database

but the problem is that when i create a sciprj file using scidavis the
mime-type associated in nautilus is text/html

Someone could help me to clarify this ?

Thanks

Eric