"Color backface" bleed on surface edges

I have my shaded mode set to color backfaces. In the linked video, with an open object, the color is bleeding through some of the closed edges. The object you see is only open where the type is inset in the lower left corner. All the other edges are closed. The effect is best seen when the surface edges are not shown, but still shows up with them showing. If I close the object via Cap, the bleed disappears - probably because Rhino knows the object is closed and therefore cuts the backface display. I guess this might be a graphics card/driver problem (Quadro 4000) but I just thought I’d throw it out here and see if anyone has had the same problem…

Thanks, --Mitch

Yeah, I see this too- - just one pixel wide, and it hides behind the front-most surface edge. No idea what the prognosis is, but I’ll add this to the pile.