Symptoms
When you migrate a Microsoft Transaction Server (MTS) application to COM+, and you do not call the SetComplete or SetAbort method, an Access Violation may occur, and the application may fail (crash). This problem occurs in COM+ (Windows 2000 Service Pack 1) and not in MTS.
Resolution
This problem occurs when non-root transactional objects release the object reference to their parent object and do not call SetComplete or SetAbort explicitly at the end of the method.
This problem is caused by a difference in the activation and deactivation mechanisms between COM+ and MTS. In COM+, if the child object does not set the done bit to true (if it does not call the IObjectControl::SetComplete or the IObjectControl::SetAbort method, does not call the IContextState:setCompletion method, or does not use Auto-Completion), the COM+ interception layer deactivates the parent object before the child object. In fact, you do not need to set the done bit, even if it is preferred in most situations.