Thankyou for taking the trouble to reply
here is a section of code that should demonstrate what i mean

use strict;
use warnings;

use Tk;
use Tk::MatchEntry;

my %data = (
    a => [qw/Abberley Abberton Abbotsley Aberaeron Abergele Abingdon A
+ccrington Achany Acton Adderley Airth/],
    b => [qw/Babraham Bacton Barrow Barry Barton Baslow Bath Battle Ba
+xenden Bexhill Bradfield/]
    );
my $place;

my $mw = MainWindow->new (-title => "i wish this would work",);
$mw->bind('<Configure>' => sub{
        my $xe = $mw->XEvent;
        $mw->maxsize($xe->w, $xe->h);
        $mw->minsize($xe->w, $xe->h);
});


my $me = $mw->MatchEntry (
                            -textvariable   => \$place,
                        -choices    => [keys %data],
                        -ignorecase => 1,
                        -maxheight  => 10,

                        -onecmd => \&repopulate,
                    #    -entercmd => \&calc,
                        )->pack (-side => 'left');
         
my $me_subwidget = $me->Subwidget('entry');
        $me_subwidget->configure(-width => '41',
                            -label => 'Starting at ',
                                );
        
    my $c = $mw->Button(
      -text => "Exit",
      -command => sub {
          $mw->destroy;
         exit;
      },
    );
    $c->pack(-anchor =>  'se',
            -padx =>10,
            -pady =>30,
            -expand => 1
            );
      
Tk::MainLoop ();


sub repopulate {
    return unless exists $data{lc $place};
    $me->configure (-choices => $data{lc $place});
}
[download]

if in the entry box i enter an 'a' then i get the list of 11 places starting with 'a' with a scrollbar
if i then enter a 'b' it reduces the list to the 6 places starting 'ab'.
so far so good.
if i then delete the b using the backspace or delete key the list expands back to the original 11 items but the scroll bar vanishes never to be seen again.
the only way round this i have found is to modify the matchenty.pm as in my original post i hope this makes more sense
Daniel