Comment 4 for bug 1044080

Fixing this is easy:
=== modified file 'UpdateManager/UpdatesAvailable.py'
--- UpdateManager/UpdatesAvailable.py 2012-10-03 15:16:01 +0000
+++ UpdateManager/UpdatesAvailable.py 2012-10-10 08:06:24 +0000
@@ -715,7 +715,7 @@
                 if not pkg.is_installed:
                     name += _(" (New install)")
                 summary = xml.sax.saxutils.escape(getattr(pkg.candidate,
- "summary", None))
+ "summary", ""))
                 if self.summary_before_name:
                     contents = "%s\n<small>%s</small>" % (summary, name)
                 else:

Its a bit puzling that summary is empty though.