Error parked document workflow

Hi all,

I have used standard configuration for parked document workflow (both FI and MM workflow).But i get some errors when run that workflows.

First, some documents go to all levels of workflow normal after user chooses "save as complete", but it cannot be posted after released by the final level, when i repeat "save as complete" and continue release, this document has been post. When i check workflow logs by SWI1, haven't any error display. This error occurs in serveral case nad make me can't control my documents. Please give me advices!!

Thanks all!