Sorry not to respond for awhile. Kevin, what is a NURBS curve, and is there any way to fix it? Same question as applied to nested symbols?
Upon more experimentation, it does seem to be something about the symbol itself, and no matter what I do it refuses to take a fill, not even with class attributes. More specifically, it seems to be my root Source 4 ellipsoidal symbol, because it affects every S4 degree I have on the plot, but my Par and LED symbols are just fine. No class or label legend changes have any effect. Experimenting with other symbols shows me that their root symbols have solid fills, whereas my S4 one has, and will accept, none.