I'm trying to create a sketch, then a fill surface based on that sketch using the code below.  If I create a fill surface using a sketch in SolidWorks normally, the sketch appears as a child to the surface in the feature tree.  However, when I do it via the API, the sketch stays where it is in the tree, and the surface appears right below it (not as a child).  Is there a way to create the surface such that the parent/child relation is shown in the feature tree (sketch as a child to the fill surface)?

If I look at the parent/child viewer, the relation is correct, the surface is a child to the sketch (same for the API method and the manual method).

Any help would be appreciated.

SketchManagersketchManager = doc.SketchManager;

...

sketchManager.CreateSplinesByEqnParams2(paramData);

...

IFeatureManager featMan = doc.FeatureManager;

int [] curvatureControlTypes = new int[] { (int)swContactType_e.swContact };

Sketch[] sketchBoundaries = new Sketch[] { sketchManager.ActiveSketch };

featMan.InsertFillSurface2(3, (int)swFeatureFillSurfaceOptions_e.swMergeResult, sketchBoundaries, curvatureControlTypes, null, null );

...

sketchManager.InsertSketch(true);