gnome-media package build issue

[Christian Schaller <uraeus linuxrising org>]

I am trying to build gnome-media with GStreamer 0.7.1. It compiles after
some tweaking of the configure file to look for 0.7. However when I try
to build an rpm it gives me the following error:
/bin/sh ../mkinstalldirs
/var/tmp/gnome-media-2.5.0-root/usr/share/pixmaps
 /usr/bin/install -c -m 644 gstreamer-properties.png
/var/tmp/gnome-media-2.5.0-root/usr/share/pixmaps/gstreamer-properties.png
/bin/sh ../mkinstalldirs /usr/share/gnome-media-2.0/interfaces
mkdir -p -- /usr/share/gnome-media-2.0/interfaces
mkdir: cannot create directory `/usr/share/gnome-media-2.0': Permission
denied
make[2]: *** [install-gladeDATA] Error 1

Looking at configure.in I can't understand why this happens as the
interfaces directory is defined exactly the same way as the pixmaps
and icons directory and they properly pick up the RPMROOT.

Anybody have an idea what could be causing this?

Christian