What you are experiencing can be corrected by setting forcearray => 1 with XMLin(). I threw together a quick example which will demonstrate the differences. (Your sample XML file is in.xml.)

One other thing I have found to be helpful when working with XML::Simple is Data::Dumper.

#-- Sample code
use strict;
use XML::Simple;

my $mXML;

print "Without forcearray...\n";
$mXML = XMLin('./in.xml');
print XMLout($mXML);
print "\n\n";

print "With forcearray...\n";
$mXML = XMLin('./in.xml',forcearray => 1);
print XMLout($mXML);
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