Call drop after handover

Dear All
We are facing the problem of sudden call drop:
•Some times whenever handover from one cell to another cell happens, after getting the “Handover Complete” message the call gets dropped immediately.
•After analyzing the signaling trace, it has been found that instead of releasing the channel of old cell, the channel of new cell gets released.
RR Cause: Already Cleared BA Range

Kindly suggest how to get it rectified.

Regards
Arpan