QGIS » QGIS Application

I have noticed that when splitting polygons from a large polygon, then editing the attributes of the new polygons in a shp file that QGIS frequently crashes.
The order of edits is:
1) select split polygon tool
2) left click on existing border/vertex of the polygon
3) left click to create additional vertices
4) right click to close new polygon against existing border/vertex
5) select the new polygon
6) amend desired attributes
7) save (then repeat for additional polygons)
The crash tends to occur (frequently, but not every time) at step 4.

I have found that clearing the selection before saving prevents the crash.

I have attached the problem signature generated during the crash.