ServiceNow Perspectium: work notes duplicates niggle

Scenario:
a duplicate worknote ends up getting written whereby an extra update transaction from Perspectium containing the following in the xml is sent

    <work_notes>_123STREAMENTRY321_original worknotes entered</work_notes>

Not too sure how this has come about but the steps to create it were reproducible

1. Create problem ticket in ServiceNow instance 1 and send to ServiceNow instance 2
2. Wait until number returned to ServiceNow instance 1 from ServiceNow instance 2
3. Go into ServiceNow instance 2
4. Enter a comment, cick ‘post’, then immediately change the state to <some value>, click save

fix:

include some error trapping in a try>catch within the inbound transform map to ultimately set the row to ignore=true

var iWN_err=source.u_work_notes.toUpperCase().indexOf('STREAMENTRY');

if (iWN_err>-1){

                        //--known error whereby the worknote has arrived as a duplicate jumbled string from TSFN

        sErrMsg='STREAMENTRY located in worknote string from TFSNow';

        sSessionErr=sErrMsg;

        throw (sErrMsg);

}