Frederick,
What happens if you set a button's Default to True? Try it with both TButton and TBitBtn. I see this in the Carbon widgetset:
procedure TCarbonCustomButton.SetDefault(ADefault: Boolean);
begin
OSError(
SetControlData(ControlRef(Widget), kControlEntireControl,
kControlPushButtonDefaultTag, SizeOf(Boolean), @ADefault),
Self, 'SetDefault', SSetData);
end;
procedure TCarbonBitBtn.SetDefault(ADefault: Boolean);
begin
// not supported
end;
So it seems like it should work with TButton but not with TBitBtn. If not, include your sample app that demonstrates the problem with your bug report.
Thanks.
-Phil