software-properties-gtk won't start

[Emilio]

Trying to run software-properties-gtk fails with a python traceback (attached). It seems that a distribution template is missing. This bug also makes the "Repositories" menu in Synaptic fail, as it uses this program.

I'm using an installed version of today's (21/01/09) daily Jaunty ISO. Do not hesiate to ask for any extra information.

ProblemType: Crash
Architecture: amd64
DistroRelease: Ubuntu 9.04
ExecutablePath: /usr/bin/software-properties-gtk
InterpreterPath: /usr/bin/python2.5
Package: software-properties-gtk 0.71
PackageArchitecture: all
ProcAttrCurrent: unconfined
ProcCmdline: /usr/bin/python /usr/bin/software-properties-gtk
ProcEnviron:
 PATH=(custom, no user)
 LANG=es_AR.UTF-8
 SHELL=/bin/bash
PythonArgs: ['/usr/bin/software-properties-gtk']
SourcePackage: software-properties
Title: software-properties-gtk crashed with NoDistroTemplateException in get_sources()
Uname: Linux 2.6.28-4-generic x86_64
UserGroups: