Using filter with collapsed keyrings leads to crash

To reproduce:
1. Open Seahorse. The "login" keyring is visible, collapsed.
2. Type some text in the "Filter:" text entry; press Enter.
3. Click the expander next to the login keyring.

Observed:
- Several dozen copies of the "login" keyring and of each match for the filter text appear.
- Hundreds of copies of the following appear on the terminal:

(seahorse:32053): Gtk-CRITICAL **: gtk_tree_model_sort_convert_iter_to_child_iter: assertion `valid == TRUE' failed
(seahorse:32053): Gtk-CRITICAL **: gtk_tree_model_filter_get_value: assertion `GTK_TREE_MODEL_FILTER (model)->priv->stamp == iter->stamp' failed
(seahorse:32053): GLib-GObject-CRITICAL **: g_object_set_property: assertion `G_IS_VALUE (value)' failed
(seahorse:32053): GLib-GObject-CRITICAL **: g_value_unset: assertion `G_IS_VALUE (value)' failed

- Clicking on any one of these causes Seahorse to crash with a segmentation fault.

Expected:
- The "login" keyring expands, with only one row per match for the filter text.

Additional information:
- When Seahorse is started, the following appears on the terminal:

(seahorse:480): GLib-GObject-CRITICAL **: Property 'icon' on class 'SeahorsePkcs11Certificate' has type 'gchararray' which is different from the type 'GIcon', of the property on interface 'GcrCertificateIface'

- The icon in the "Filter:" text entry is the gtk-missing-image stock icon.

$ lsb_release -rd && apt-cache policy seahorse
Description: Ubuntu 11.10
Release: 11.10
seahorse:
  Installed: 3.2.2-0ubuntu0.1
  Candidate: 3.2.2-0ubuntu0.1
  Version table:
 *** 3.2.2-0ubuntu0.1 0
        500 http://mirrors.mit.edu/ubuntu/ oneiric-updates/main amd64 Packages
        100 /var/lib/dpkg/status
     3.2.0-0ubuntu1 0
        500 http://mirrors.mit.edu/ubuntu/ oneiric/main amd64 Packages