All,
The Knife plugin has been updated to version 1.3.
http://supercoldmilk.com/knife.html
This release enforces a per-surface slice of all edges.
Before this release, all surfaces of the knife were thrown at the cut object at once, which sometimes caused seemingly random slicing. This fix forces a per-surface slice.
In the above image, you see an object being sliced by a 30 surface knife.
The first slice uses the pre-1.3 knife - you can see the misplaced cuts here, and the absence of cuts along a section of the upper-left of the object.
The second slice uses the 1.3 knife - because surfaces are sliced in order, this works as expected.
This does remove a rather esoteric feature of the knife, however:
The left-most image shows a rectangle with two intersecting surfaces that have been Merged into one object. Not an ideal Knife, but it works.
The knife slices in the pre-1.3 version between the two surfaces.
However, in 1.3 (right-most image), because slices are performed per-surface, this slice does not take place. The vertices are inserted where expected, but there is no slice.
I believe this is still favorable to the old version. Feel free to comment on whether the old version's method would be preferable in any way.
Dennis