Listbox of JComboBox displayed on different screen

[tmf]

Dear Monks,

I have a problem using TK::JComboBox for my GUI.

The programm works fine and the combobox does exactly what it is supposed to. When the application is run on the second screen (using two monitors on the computer, not the main one) the listbox is being displayed on the first screen (main monitor), while the rest of the GUI is still on the other one. I do not have a lot of experience with Perl and I would be very grateful if anybody could tell me why this happens and how to change this.

Here is a small code fragment for a JComboBox. It doesn't do anything, but the problem occurs with it as well.

use Tk::JComboBox;

my $sMain;
    
$sMain = MainWindow->new();
$sMain->minsize(qw(700 400));

my $sBox = $sMain->JComboBox(-entrybackground => 'white',
    -choices => [qw/one two three four/],
     -mode => 'editable',
     -relief => 'sunken',
     -entrywidth => 70 ,
  )->grid(
   -row    => 1,
   -column => 1,
   -sticky => 'n',
  );

MainLoop;