update-manager UI freezes if gconfd frobbed

I originally wrote comments in https://bugs.launchpad.net/update-manager/+bug/485495 but I missed that the bug was specific to performing a dist-upgrade. My bug is not related to dist-upgrades but normal run-of-the-mill updates.

My gconfd seemed to be broken for some reason (yet to be confirmed). As a result:

 * update-manager couldn't talk to gconfd and essentially froze after clicking "Install Updates" (although only the UI froze, it was looping through an infinite-retry cycle in the background as the strace below demonstrates). The stderr output from update-manager on clicking update was:

Unhandled exception in thread started by <bound method InstallBackendSynaptic._run_synaptic of <UpdateManager.backend.InstallBackendSynaptic.InstallBackendSynaptic object at 0xa5cb4ec>>
Traceback (most recent call last):
  File "/usr/lib/python2.6/dist-packages/UpdateManager/backend/InstallBackendSynaptic.py", line 37, in _run_synaptic
    if gconfclient.get_bool("/apps/update-manager/autoclose_install_window"):
glib.GError: Failed to contact configuration server; some possible causes are that you need to enable TCP/IP networking for ORBit, or you have stale NFS locks due to a system crash. See http://projects.gnome.org/gconf/ for information. (Details — 1: Server ping error: IDL:omg.org/CORBA/COMM_FAILURE:1.0)

 * update-manager, when clicking "Check", couldn't elevate priviledges, most likely due to gconfd being stuck, and reported a misleading error message:

"Failed to run /usr/sbin/synaptic '--hide-main-window' '--non-interactive' '--parent-window-id' '67108908' '--update-at-startup' as user root.

Wrong password."

the strace:

read(4, 0x8ac2868, 4096) = -1 EAGAIN (Resource temporarily unavailable)
gettimeofday({1279891766, 151819}, NULL) = 0
poll([{fd=5, events=POLLIN}, {fd=4, events=POLLIN}, {fd=7, events=POLLIN}, {fd=8, events=POLLIN}, {fd=12, events=POLLIN|POLLPRI}, {fd=14, events=POLLIN}, {fd=31, events=POLLIN}, {fd=3, events=POLLIN}], 8, 0) = 0 (Timeout)
gettimeofday({1279891766, 151911}, NULL) = 0