glade isn't registered to open ui files in nautilus

[Chris]

Double clicking on a .ui file in nautilus or running xdg-open window.ui doesn't open the file in Glade.

Glade isn't in the list of applications in the nautilus right click menu either.

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: glade-gnome 3.8.0-0ubuntu4
ProcVersionSignature: Ubuntu 3.2.0-10.17-generic 3.2.1
Uname: Linux 3.2.0-10-generic x86_64
ApportVersion: 1.91-0ubuntu1
Architecture: amd64
Date: Mon Jan 23 21:59:35 2012
InstallationMedia: Ubuntu 11.10 "Oneiric Ocelot" - Beta amd64+mac (20110901)
ProcEnviron:
 LANGUAGE=en_GB:en
 PATH=(custom, no user)
 LANG=en_GB.UTF-8
 SHELL=/bin/bash
SourcePackage: glade-3
UpgradeStatus: Upgraded to precise on 2012-01-21 (2 days ago)