I have an assembly that I am inserting a new component into.  I start a new sketch and start adding relations however, SolidWorks will not let me select or add relations to two of the edge flanges in one of the existing components in my assembly.

Also, if I open the problem component I can select all of the other features of the component without any problems but the two suspect edge flanges do not highlight when clicking on them. Could this be a glitch cause by having an edge flange feature with more than 6 edges selected?

Very frustrating. Anyone have any ideas? I have included the assembly file with the base sketch of the part I need to add. I am trying to add colinear relations to the GH 007-01 part.