Immediately after updating to iOS 4.0, some users may notice that Exchange ActiveSync Mail, Contacts, or Calendars do not sync, or sync very slowly. In addition, some Exchange Server administrators may notice their servers running slowly.

It is important to create frequent backups of important data. This is even more important if you are using beta software. You should make sure you back up your data prior to entering the MobileMe Calendar Beta.

Immediately after updating to iOS 4.0, some users may notice that Exchange ActiveSync Mail, Contacts, or Calendars do not sync, or sync very slowly. In addition, some Exchange Server administrators may notice their servers running slowly.