After I scan a document, it goes twice to the Post Scan event.
First time is good, but then immediately it enters another time to this event.
What can be the reason?

I'm registered only once to the event:
VSTwainDocument.PostScan += new AxVSTWAINLib._IVintaSoftTwainEvents_PostScanEventHandler(VSTwainDocument_PostScan);
Thanks ahead,
Vanilla