I know Charles, we all scratch our heads - alot! I would double check that frame and the frame ajoining it. Make sure that the foundation isn't warped at all, that the frames are hanging perfectly straight (no torque). Until the girls draw that foundation out, they have too much room to mess with. You might want to move that frame (and maybe the ajoining one too) to the outside of the box (on opposite sides) just to give the girls a 'fresh start' on two other frames.
Do you arrange your frames according to housel positioning? I don't have the link for it right here - maybe just do a search on this site (or even google) and it will come up. But it's a simple, no-cost manipulation of the frames, and it might help keep the girls from going crazy on the comb building.