mailNickname attribute does fails to update. Constraint violation.
source domain has mailNickname value as an invalid format.
Exchange 2000 and Exchange 2003 have no problem with users (or groups and contacts) which have a space in their mailNickname attribute. Unfortunately if you try to synchronise with one of these users using Exchange 2007 or Exchange 2010 you will get a constraint violation error.
Make sure the source alias does not contain space characters or any of the following characters:
@ () \ : ; ~ , [ ] < >