I have a user with an iPhone 4S that just reported to me that they noticed numerous contacts missing from their phone, which also syncs with their company Exchange account. The common thread with the missing contacts is that they were strictly phone contacts (i.e. they're not in the contacts for Exchange/Outlook). Our company just set up an Exchange 2010 server and migrated to it the weekend before Christmas (from our Exchange 2003 server), but I haven't been able to determine if the contacts went missing after that or if they were missing before that and just not noticed. Other than the change in Exchange server level and the new server, the only other change was to go to Autodiscover as recommended for Exchange 2010, with our server entry on the phones changing from servername.domain.com to mail.domain.com. Could that have affected users somehow?