So how can i see what is $mech actually sending?

As the documentation says, WWW::Mechanize is a subclass of LWP::UserAgent, so the approaches outlined in LWP::Debug all hold for WWW::Mechanize as well.

But that i what i wrote i used....

use LWP::UserAgent;
  $ua = LWP::UserAgent->new;
  $ua->default_header('Accept-Encoding' => scalar HTTP::Message::decod
+able());

  $ua->add_handler("request_send",  sub { shift->dump; return });
  $ua->add_handler("response_done", sub { shift->dump; return });

$ua->get($mech->uri);
[download]

And apparently it doest show the correct info????