message path help

[Shao Sean]

if i am to understand the message path correctly any groups with  
backgroundBehavior set to TRUE will be behind the card in terms of  
the message path, but the follow does not work

- create new stack
- create three buttons (A, B, C)
- group button A
-- group script: on moo; put the seconds; end moo
-- group properties: set the backgroundBehaior to TRUE
- button B & C script: on mouseUp; moo; end mouseUp
- group button C

click on button B, the code works
click on button C, the code does not work

Now my understanding of the message path is something like this:
frontScript > control > parentScript > group > card > background >  
stack > backScript > library > mainStack > engine

should the above example work?