Steps to reproduce :
Agent 1 makes outbound call to User
Agent 1 blind/attended transfers call to Agent 2.
Now Agent 2 and User are in call

The AES TSAPI sends call back for Call Transfer .However the AES TSAPI doesn't send any callback for "CallCleared" for the Agent 1.
This behavior is NOT reproducible in the following scenario, as AES TSAPI is sending callback for both Call Transfer and Call Cleared.

User Makes a call and Agent 1 receives the call
Agent 1 blind/attended call to Agent 2
Now Agent 2 and User are in call

Events from Communication Manager can vary slightly, depending on call flow and internal organisation. I think the Transferred event should give all the information required.

Martin