The most important thing here is that you're not checking $@. Using eval and then throwing away $@ means you've lost the most important clue as to what's going on!

It looks like the service is not using basic authentication, but Soap Header authentication.

I think the code is going to look something like this:

use SOAP::Lite;
use strict;
my $service = SOAP::Lite
            -> service('http://server/GetData.asmx?WSDL');

my $AuthHeader = SOAP::Header->new(
  name =>'AuthenticationHeader',
  attr => { xmlns => "http://www.server.com/" },
  value => {username => 'user', password => 'pass' },
);
my $result = $service->GetIt($AuthHeader);
[download]

Without seeing the WSDL, I can't be sure--not that I'm a SOAP expert.