Fillet tool does not stop at selected edges?

[jfitch]

I am trying to the the fillet tool to do some round overs on a machine part solid model. The way it used to work is that the fillet would (usually) stop at the vertex at the end of the selected edge segment. It would stop just as though you were using a round over router bit and lifted it or pulled it away from the work at that point.

Now, in 2011, the fillet continues on tangent to the last edge until it clears the part. Sometimes it just continues on around the edge of the surface regardless of whether the next segment is selected for filleting or not. The "select tangent edges" option is not selected, nor is the face option selected. I have tried every combination of these, also adding extra vertices of different types in the polyline from which the solid was extruded, etc. all without success.

Can someone explain to me how to reliably get the fillet to stop? I'm having trouble reverse engineering this tool....

[jfitch]

Here is an attached example. This is a simple extruded solid. The only edge selected for filleting is the upper left hand semicircle. Notice that it has filleted down both sides until it could find no more material to fillet. The break in the near edge shows how it runs off the material tangent to the last edge it has decided to fillet. It has similarly damaged the far edge of the left hand semicircle.

If you do this same operation a few revisions back it looks very different: only the chosen left hand semicircle is filleted, stopping at the straight segments.