work around the fact that PHP bizarrely prepends a dot to specified cookie domain names

lib/session.php

@@ -34,11 +34,11 @@ private $datahash='';		// hash of data field
 	// Create a new (insecure) session
 	private function newsession()
 	{
-		global $DB;
+		global $DB, $preferred_hostname;
 
 		$token = $this->genSessionID(); 
 		$DB->Execute("insert into {$this->table} (hash, lastseen, ip) values (?,NOW(),?)", array($token, $_SERVER['REMOTE_ADDR']));
-		setcookie("sucssite_session", $token, NULL, "/");
+		setcookie("sucssite_session", $token, NULL, "/", $preferred_hostname);
 		$this->token = $token;
 		return;
 	}