Win7 x64
Outlook 2010 32bit
Zimbra server ver 7.2.4

Zimbra::Sync::GalSynchronizer::OnForceSyncTimer: Begin
07-11-2013 12:50:52.319 [4824]: QueryInterface this(051D6E40) inner(035F1A58) iid(Unknown MAPI Interface (31)): unknown handled by inner as 035F1A58
07-11-2013 12:50:52.460 [4824]: QueryInterface this(051D6E40) inner(035F1A58) iid(Unknown MAPI Interface (31)): unknown handled by inner as 035F1A58
07-11-2013 12:50:52.522 [4824]: QueryInterface this(051D6E40) inner(035F1A58) iid(Unknown MAPI Interface (31)): unknown handled by inner as 035F1A58
07-11-2013 12:50:52.522 [4824]: QueryInterface this(051D6E40) inner(035F1A58) iid(Unknown MAPI Interface (31)): unknown handled by inner as 035F1A58
07-11-2013 12:50:53.255 [4824]: QueryInterface this(051D6E40) inner(035F1A58) iid(Unknown MAPI Interface (31)): unknown handled by inner as 035F1A58
07-11-2013 12:50:53.427 [4824]: QueryInterface this(051D6E40) inner(035F1A58) iid(Unknown MAPI Interface (31)): unknown handled by inner as 035F1A58

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This is mailbox used by 50 users for shared contacts and calendaring data. Just recently we've had two users report that their changes are not being sent and they are not seeing the changes that others have made. we've upgraded their zco from 7.1.x to 7.2.4; we rebuilt the mailbox, we recreated the profile and reset the cached data.
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