Index: gnome-control-center-3.4.0/panels/user-accounts/um-user.c
===================================================================
--- gnome-control-center-3.4.0.orig/panels/user-accounts/um-user.c	2012-04-10 09:45:21.318382748 -0400
+++ gnome-control-center-3.4.0/panels/user-accounts/um-user.c	2012-04-10 09:48:21.290384652 -0400
@@ -846,7 +846,7 @@
         GVariant *result;
         GError *error = NULL;
 
-        result = g_dbus_proxy_call_sync (user->proxy, "SetIconFile", g_variant_new ("(s)", icon_file), G_DBUS_CALL_FLAGS_NONE, -1, NULL, &error);
+        result = g_dbus_proxy_call_sync (user->proxy, "SetIconFile", g_variant_new ("(s)", icon_file ? icon_file : ""), G_DBUS_CALL_FLAGS_NONE, -1, NULL, &error);
         if (!result) {
                 g_warning ("SetIconFile call failed: %s", error->message);
                 g_error_free (error);
