Underlay acting as Overlay

I have a problem doing upper and lower plans. For my lower level plans I set my view range from 0 to 1400 or so. For my upper level plans I set my view range from 1400 to level above. I then use an underlay of the current level to show the lower level elements as half tone. The problem is that several elements (mainly plumbing fittings) are being obscured by the underlay and are being made half tone.

For a 2 minute screen capture video of my issue, please follow this link: http://screenr.com/QRW8

Thanks!