Button Hilite Behavior

[Rob Cozens]

Hi All,

My morning mystery involves a group consisting of three buttons and a 
background field in which the buttons are framed.

There is one check box button, "Add Handlers?", family 0 and two 
radio buttons, "SDB UI" and "HC UI", family 1.  The enabled property 
of "SDB UI" & "HC UI" is toggled to match the hilite property of "Add 
Handlers?".  When enabled, "SDB UI" & "HC UI" should toggle as 
mutually exclusive options.

The problem is that selecting the unhilited radio button unhilites 
"Add Handlers?", even when I explicitly hilite it by script 
(autoHilite is off):

The pertinent handler is in the group script:

on mouseUp
   if "button" is not in the name of the target then exit mouseUp
   play audioClip "click.au"
   lock screen
   switch (the short name of the target)
     case "Add Handlers?"
       get not the hilite of button "Add Handlers?"
       set the hilite of button "Add Handlers?" to it
       set the enabled of button "SDB UI" to it
       set the enabled of button "HC UI" to it
       break
     case "SDB UI"
       get the hilite of button "SDB UI"
       set the hilite of button "HC UI" to it
       set the hilite of button "SDB UI" to not it
       set the hilite of button "Add Handlers?" to true
       break
     case "HCB UI"
       get the hilite of button "HC UI"
       set the hilite of button "SDB UI" to it
       set the hilite of button "HC UI" to not it
       set the hilite of button "Add Handlers?" to true
       break
   end switch
   unlock screen
end mouseUp

After running this handler and toggling the radio buttons, typing 
'set the hilite of button "Add Handlers?" to true' in the Message Box 
gives me back my check in the box.

Can anyone tell me why the checkmark (hilite) is going away in the first place?

TIA,

Rob Cozens
CCW, Serendipity Software Company
http://www.oenolog.net/who.htm

"And I, which was two fooles, do so grow three;
Who are a little wise, the best fooles bee."

from "The Triple Foole" by John Donne (1572-1631)