ZCB Syncing of Calendar Failing

[mckoz]

A fresh install yesterday, and fresh activations. The calendar syncing worked for about four or five hours then hung with the following errors:

[[40267] (01/28 09:53:51.132):{0x1410} {user@domain.org} Starting calendar rescan
[40136] (01/28 09:53:51.132):{0x1410} CalICSAgent::GetDirectoryName synch directory retrieved from registry: C:\Program Files\Research In Motion\BlackBerry Enterprise Server\Agents\ICSSync\ for user@domain.org
[10007] (01/28 09:53:51.132):{0x1410} CalICSSynchronizer::Initialize - OpenProperty failed: (0x80004002)
[20041] (01/28 09:53:51.132):{0x1410} CalICSAgent::Start Could not Initialize Synchronizer for user@domain.org: (0x80004002)
[30020] (01/28 09:53:51.132):{0x1410} {user@domain.org} MAPIMailbox::DoICS ICS Start failed
[20280] (01/28 09:53:51.132):{0x1410} {user@domain.org} DoICS() failed: ERR_FAIL
[40701] (01/28 09:53:51.195):{0x1410} {user@domain.org} Calendar rescan completed

This is my fourth clean install this week, and I would very much like to track this error down, as my users are getting a bit impatient with me and the wipe and reactivate....