iirc, they got broken when we passed in video_update from
for (y = cliprect->min_y; y <= cliprect->max_y; y++)
snes_refresh_scanline(screen->machine, bitmap, y);
to
for (y = cliprect->min_y; y <= cliprect->max_y; y++)
snes_refresh_scanline(screen->machine, bitmap, y+1);
(notice the y
+1). I've never gone back to fix them