Terminating event received

[Alexesca]

Hi, all, please your help to resolved an issue that happens with an workflow template por Purchase order approval.
This issue consist in when a final approver did his approval throw workflow, from his SAP Business Workplace,after that if you display purchase document from ME23N transaction, you can see that this approval it´s pending, and if you display the workflow log for this workitem, a warning message appears for the task TS92000301 of approval, that message indicate that user WF-Batch is "Unable to process event-work item has a final status".
The workflow template i´m refer it´s WS92000018.
Thanks for all of your help.