Setting to restore edge-lines in SOLDRAW ISO view

[cfee]

What's the setting to restore edge-lines in SOLDRAW ISO view? I've got Rect-Tbg members where the tangent curve edge-lines aren't showing up. Specifically- if you extrude the cross-section of a rectangular tubing member, the outside corners along the length of the tube are rounded. All of the sharp edges describing the end-face-to-sides edges show fine, and the edges representing the transition from the front vivible sides around to the rear sides (invisible) show just as they should. However, the double-lines representing the forward curved corner of the extruded member seem to not show, because the "show tangential curves" setting is (by default) "off". I can't find the dialog that changes that setting. I looked in "options" where I thought I remembered it, but no luck.
Any Suggestions?
Tks-
C.Fee