You could also try HTTP::Lite

use strict;
use warnings;
use HTTP::Lite;

my $url = 'http://ecs.amazonaws.com/onca/xml?Service=AWSECommerceServi
+ce&Version=2005-03-23&Operation=ItemSearch&ContentType=text%2Fxml&Sub
+scriptionId=xxxxxxxxxx&SearchIndex=Music&Keywords=5099921688607&Respo
+nseGroup=OfferFull,Small';

my $http = new HTTP::Lite;

my $req = $http->request( $url )    or die "Unable to get document: $!
+";
print $http->body(), "\n";
[download]

For me, this returns the same complaint noted by Khen1950fx, but that's also what I get with LWP::Simple