It's really simple to sync by BT.
1. Add an incoming COM port in Your PDA.
2. Define by PDA a new partnership with Your PC BT.
3. Discover Your PDA BT services by using Your PC BT dongle software.
You'll find serial service available (thanks to the incoming COM port added on Your PDA).
4. So You'll be able to establish a serial connection by BT directly by the software of Your PC BT dongle. Do it.
5. You'll also notice Your dongle offers a COM port. Ok, You've to enable in PC ActiveSync the connection to this COM port offered by Your BT dongle.
5. Now edit on Your PDA the BT partnership and refresh the services.
You'll find ActiveSync in place of serial port service (on the PDA screen).
6. Enable-select ActiveSync service and click finish (by Your PDA).
7. Execute ActiveSync on Your PDA.
8. Click connection by bluetooth. Your PDA now will find there is already a BT partnership with activeSync service enabled.
9. You're ready to use ActiveSync by BT
I hope it helps.