[Derek_Trotter]

OK. I find solution!
My forum's archive is now gzip compressed.
I put this line of code:
if (substr_count($_SERVER['HTTP_ACCEPT_ENCODING'], 'gzip')) ob_start("ob_gzhandler"); else ob_start();

in file archive/index.php

I place it here:
// #################### DEFINE IMPORTANT CONSTANTS #######################
define('SESSION_BYPASS', 1);
define('THIS_SCRIPT', 'archive');
if (substr_count($_SERVER['HTTP_ACCEPT_ENCODING'], 'gzip')) ob_start("ob_gzhandler"); else ob_start();

// ################### PRE-CACHE TEMPLATES AND DATA ######################

To see is it you archive gziped go to website for gzip testing:
http://www.gidnetwork.com/tools/gzip-test.php

Enjoy