Question : Problem: WM 6.1 device's calendar return an error: "cannot synchronize appointment"

I use Exchange Server ActiveSync to synchronize my mobile phones with Exchange 2007.
I have multiple users that use the ATT Tilt with Windows Mobile 6.1. They all sync email, calendar, tasks, and contacts via active sync.
All devices receive all updates from the Exchange Server, but changes or new appointments in the WM6.1 device's calendar return an error: "cannot synchronize appointment" when synchronizing.
This puts the active sync on the device into a loop that never ends and eventually kills the battery because it is trying to sync the calendar item that was added via the device.  I have tried un-syncing the device and even a hard reset of the device with no avail.  Any windows mobile 6 device on the same exchange server works just fine it is only the devices on 6.1.

Any help is appreciated. Thanks.

Answer : Problem: WM 6.1 device's calendar return an error: "cannot synchronize appointment"

It is a problem with Daylight savings time.

On your device, switch the time zone to someplace without DST (I used arizona)
Sync your device
Change the time zone back to the correct one.
Sync again
I am now able to sync calendar items both directions.