diff -r 3a6ddacb7198 -r a464deecc9dd mercurial/obsolete.py
--- a/mercurial/obsolete.py	Thu Dec 20 15:32:42 2012 +0100
+++ b/mercurial/obsolete.py	Thu Dec 20 17:14:07 2012 +0100
@@ -738,6 +738,7 @@
             if nprec in nsucs:
                 raise util.Abort("changeset %s cannot obsolete itself" % prec)
             repo.obsstore.create(tr, nprec, nsucs, flag, metadata)
+            repo.filteredrevcache.clear()
         tr.close()
     finally:
         tr.release()