[htmltmpl] h::t on different platforms

[Puneet K. <pk...@ei...>]

The following works fine on both MacOS X (Perl 5.6.0) and Windows XP 
(Perl 5.8.0).

my $f = sub { my $t = shift; $$t =~ s/<!--#.*?-->//g; };
my $template = HTML::Template->new(
               filename => index.tmpl,
               global_vars => 1,
               loop_context_vars => 1,
               filter => $f
                  );

However, the following works fine on MacOS X

my $template = HTML::Template->new(
               filename => index.tmpl,
               global_vars => 1,
               loop_context_vars => 1,
               filter => sub { $$ =~ s/<!--#.*?-->//g; }
                  );

but gives the following error on Windows XP

HTML::Template->new() : fatal error occured during filter call: 
Modification of a read-only value attempted at 
D:/htdocs/perlpim/cal/index.cgi line 28.
  at D:/htdocs/perlpim/cal/index.cgi line 29

Line 29 is filter => sub { $$ =~ s/<!--#.*?-->//g; }

what gives?

Thanks.