My company is using ACT! 2009, Exchange 2007, and iPhones. We've been running into issues with the Calendar sync between Outlook & ACT resulting in gross amounts of duplicate entries. Some users are experiencing fewer duplications than others. We have ACT scheduler setup to sync both ways between Outlook and ACT on an hourly basis from 8am to 5pm. I have turned off the calendar sync & cleaned up all duplicates and have seen no new duplications. However, upon turning the sync back on I start to gradually see duplications start up again. Can anybody give me any advice on how to avoid this problem and still sync.