Hi
Had the same problem and in the end found out that this is connected to time zone.
You can see in the event log of the BES a message that will tell you there was a sync problem.

If so make sure that the Handheld and the BES are on the SAME time zone.

if the handheld time zone is different (GMT+X) the meetings created on the device are not synced and you will see a warning in the BES event log at the time the meeting was created.

Hope this will help.