Why isn't iPhone syncing Calendar items with Outlook? I am trying to set up a new (Verizon) iPhone to sync Contacts and Calender entries with Outlook 2007 on a Windows Vista Ultimate PC. The Contacts sync both ways, and calendar entries created in Outlook sync to the phone, but calendar entries created on the phone don't sync back to Outlook. I only have one calendar in Outlook. How can I get the calendar items created on the iPhone to sync back to Outlook?
The best troubleshooting I have found for this problem is iPhone, iPad, iPod touch: Troubleshooting contact and calendar syncing via USB on Windows(Apple), mainly due to the fact that it explains how to reset sync history in iTunes, a process that reevaluates the contents of both devices and tries to resync them.

Another good little trick is to try a "Replace data on this iPhone" near the bottom of the info tab, that will wipe the specific data set off the iPhone and replace it with the computers, often a good way to get them talking to each other again.