Hello Monks,
I have a DialogBox with 2 Listboxes each in its respective Frame. The Selection of both Listboxes is 'multiple' as selection mode.
Selecting multiple items works fine unless I decide to select items in both listboxes, which causes the selection in the inactive listbox to be deleted.
I am using AS Perl Build 510 ( 5.8.4) on XP.

 $obj->{ lb_class } =
    $f_class->Listbox( -selectmode => 'multiple',
               -width => 30,
               -height => 12,
               -listvariable => $obj->{class}
     )->grid( -row => 0,-column => 0 );

  my $f_type = 
    $obj->{ "dlg" }->Frame( -relief => 'groove',
                -borderwidth => 2
              )->grid( -row => 1,
                   -column => 1 );

  $obj->{ type } = [( ...)];

  $obj->{ lb_type } =
    $f_type->Listbox( 
      -selectmode => 'multiple',
      -width => 30,
      -height => 12,
      -listvariable => $obj->{type} 
   )->grid( -row => 0,
            -column => 0 );
[download]

Thanks