need urgent session help, since new php version broke my code

Hi all all the links in my page link to not existing html pages. i redirect the 404 to a php script. when users had disabeled cookies, i parsed the request_uri for phpsessid and then set $HTTP_GET_VARS['PHPSESSID']=the parsed one. when i after that called session_start(), php was using the id from $HTTP_GET_VARS['PHPSESSID']. after upgrade to the latest php version this does not work anymore. i get a new PHPSESSID on every request. is there any way to keep the sessionid with these redirects? *extremecryforhelpsincepageisbrokenfornoncookieusers* Sebastian