really simple question

[S . Woodside]

The following code in Provider.pm get_xml_info():
        if($@) {
                my $str_ref = $self->get_strref();
                $r->pnotes('xml_string', ${$str_ref});
                @ret = parse_xml_info( $r, undef, $str_ref, $media, 
$pref_style);
        }
        return @ret;

Now if I add a debug statement like this:
        AxKit::Debug(10, "SIMON get_xml_info str_ref = ".${$str_ref});
I get what I'd expect, e.g. the XML document printed out.
But if I add this:
        AxKit::Debug(10, "SIMON get_xml_info pnotes('xml_string') = 
".$r->pnotes('xml_string'));
then I get nothing. What am I doing wrong?

simon