If you are on Windows then Win32::IE::Mechanize can work where the "Mech" can't (e.g javascript hurdles). It can help to view frame info with something like Firefox's Web Developer add-on to work out form info.
Example code ...

use Win32::IE::Mechanize;
my $mech = Win32::IE::Mechanize->new(visible => 1);
# Connect to server
$mech->get( "http://web_server:8080" );
$mech->success or die $mech->response->status_line;

my $html = $mech->content;

# Log into server
$mech->form_name("loginform");
$mech->field('userName', 'courtenay@db.com');
$mech->field('loginPassword', '');
$mech->click_button( value => ' Login ' );

$html = $mech->content;
[download]

...etc etc