After the driver upgrade, if you see the following trace message when a user is added, verify that the value of the Default Sync Destination: GroupWise PostOffice is in dot format:
DirXML Log Event ------------------- Driver = \GW12-LNX86\system\driverset1\GroupWise-Jun10_2014 Thread = Subscriber Object = \GW12-LNX86\data\users\user (DOMAIN\PO1) Level = error Message = <code>java.lang.IllegalArgumentException: Placement Rule Destination string DOMAIN\PO1 was not found</code>