#pas
procedure TXPMenu._work_doCheckIdx;
var   Idx:integer;
begin
   Idx:= ReadInteger(_Data,_data_Index,_prop_Index);
   if (Menu.Count > 0) and (Idx >= 0 ) and (Idx < Menu.Count) then
      if Menu.ItemChecked[Idx] then
         Menu.ItemChecked[Idx]:= not Menu.ItemChecked[Idx]      // <--- why not false?
      else
         Menu.RadioCheck(Idx);
end;