XML::Simple may work great for simple stuff, and though your new requirement may still be simple, it seems like it won't take long for you to surpass that. Personally, I find XML::Twig simple enough for the simple stuff, and no more complex for the complex stuff... so I'd recommend going that way sooner rather than later.

That said, this doesn't appear to be valid XML: there is no close tag for 'report'. So it seems unfortunate that XML::Simple doesn't complain (it's not really XML anymore). Anyway, if I just close that tag immediately, I get:

#!/usr/bin/perl

use strict;
use warnings;

use XML::Twig;

my $twig = XML::Twig->new();
$twig->parse(\*DATA);

for my $node ($twig->get_xpath('/root/node'))
{
    print "Machine: ", $node->att('mid'), "\n";
    my ($values) = $node->get_xpath('values');
    print "\tvalues: ", $values->text(), "\n";
    my ($time) = $node->get_xpath('time');
    print "\ttime: ", $time->text(), "\n";
}

__END__
<root>

 <report id="0" ip="1.1.1.1" />

   <node mid="machine1" name="Winxp">
     <values>1, 2, 3, 4, 5, 6</values>
     <time>110, 120, 130, 140, 150, 160</time>
   </node>

   <node mid="machine2" name="Win2003">
     <values>1, 2, 3, 4, 5, 6</values>
     <time>110, 120, 130, 140, 150, 160</time>
   </node>

</root>
[download]

Machine: machine1
        values: 1, 2, 3, 4, 5, 6
        time: 110, 120, 130, 140, 150, 160
Machine: machine2
        values: 1, 2, 3, 4, 5, 6
        time: 110, 120, 130, 140, 150, 160
[download]