.Net exe Hung

1. I had few VB 6.0 dll.
2. Using tlbimp command we have converted this dll and consumed in .Net Appplication
3. I have implemented below code in .Net dll, But Somehow this .net exe hung sometimes. Not always. Can you suggest me Whats wrong in this?
4. Code Snippet

//calling VB DLL1 through COM component

               COMDLL1.Map comParams = null;

                comParams = new COMDLL1.Map();
                comParams.AsMap(args[0]);


                //calling VB DLL2 SystemEventControl through COM component
                COMDLL2.ISystemEventListener eListerner = null;
                eListerner = new COMDLL2.ISystemEventListener();

                //calling VB DLL3 AS_RemittanceTrigger through COM component
                COMDLL3.ExeControl comEventHandler = null;
                comEventHandler = new COMDLL3.ExeControl();


                bool comExecutionStatus = comEventHandler.ISystemEventHandler_RunProcess(ProcessID, comParams, eListerner);


if (comEventHandler != null)
                    Marshal.FinalReleaseComObject(comEventHandler);

                if (eListerner != null)
                    Marshal.FinalReleaseComObject(eListerner);

                if (comParams != null)
                    Marshal.FinalReleaseComObject(comParams);