Outlook Sync issue: erroe (0x000456)

[Shawn]

I am using outlook 2003 which contacts to exchange 2003. when I change the
outlook from non-cache mode to cache mode. the following sync problem
happened. All my contacts moved to sever failuser folder under Sync Issue
folder. I also get message as follow. Also, when I use OWA look contacts are
gone.

14:29:48 Synchronizing server changes in folder 'Contacts'
14:29:49 Downloading from server 'Exchange server name'
14:29:51 The following message had an error and synchronization of it
was skipped (0x000456):
14:29:51 "person name"

I think something is wrong with mailbox, but I do not what is wrong and how
to fix it. Any advice?

Thanks

Shawn