NX 4 Modeling - Extruding a Face starts the Sketch App

You're intention is to extrude a face. You choose the extrude icon and select the face, however, the Sketch application starts - why?

The extrude operation is expecting that you are about to sketch the extrusion profile on the face you just selected - rather than use the edges of the selected face for the extrusion profile.

There are a couple of solutions to prevent this from happening:

1. Change your selection intent to "Face Edges".
2. Uncheck "Automatically Sketch on Planar Faces" in the customer defaults [found under "Modeling > Extras" in NX4.0.2 onwards].

Note that option 2 only works if selection intent is set to "Any".