use XML::RSS ();
my $rss_content = "RSS goes here";

my @replace = (
    ['\&(\s)', '"&$1"'], # '&' followed by space
    ['(\s)>',  '"$1>"'],   # '>' with preceding space
    ['\&',     '"&"'],   # All '&'
);
my($data, $rss);
PARSE: while (my $repl = shift @replace) {
    $rss = XML::RSS->new;
    $data = eval { $rss->parse($rss_content) } and last PARSE;
} continue {
    $content =~ s/$repl->[0]/eval($repl->[1])/ge;
}
die unless $data;