Issues with saving edits of OGR layer from PostGIS

Hello, my dear friends:
I am using MapWindow.Lite demo in version 5.3.0. When I use the ShapeEditor toolbar to edit and save edits with shapefile layers, everything goes well. When I edit an ogr layer from PostGIS, it can be edited and saved normally without doing SplitByPolyline or SplitByPolygon or ClipByPolygon etc. operations. The problem is when I do some edits through SplitByPolyline or SplitByPolygon or ClipByPolygon etc. operations, the edits can not be saved to PostGIS. I tested this situations many times, and I can’t find why. Is it a Bug in MapWinGIS? Can some one give me any help?
Thank you very much, guys!