Behaving badly with backgrounds

[Richmond]

So:

1. I developed a stack with one card.

2. Populated that card with a group "GX".

3. Set the backgroundBehavior of group "GX" to true.

4. Started making new cards, and as I did so the group "GX"
     became visible on all of them.

    Lovely . . .  :)

5. As I made each new card I also created card-specific controls on that 
card.

6. Now I create a new group ("GN") on card 1 and set its backgroundBehavior
     to true.

7. Group "GN" does NOT propagate across any of the pre-existing cards . 
. .  :(

How do I get a NEW group with backgroundBehavior set to true to propagate
across a set of cards created prior to that group?