Opaque tabbed button question and RevRTFer

[Jim Witte]

   I'm looking at the RevRTFer stack here, which has a tabbed button 
covering the entire card grouped with everything else on the card.  
Originally the 'pane' part of the button is transparent, but when I 
ungroup everything, the button goes opaque, and the 'Opaque' property 
doesn't do anything, nor does the layer of the button affect it.  How do 
I get the button to go transparent again?

Jim