Lighttpd

i use,

1. lighttpd -v
   lighttpd-1.4.20 - a light and fast webserver
   Build-Date: Feb 21 2009 17:31:29 #

i installed Qmailadmin. bu i can not access /cgi-bin/ and its subfolders, like "qmailadmin/qmailadmin".
i googled and searched in this forums but i could not find any usefull information and so could not solve my problem.
last, i accessed /cgi/bin/qmailadmin/qmailadmin. but this time my browser tried to download "qmailadmin" file.

finally, i am getting a white webpage and the error with the config below.

lines includes "cgi" in Lighttpd.conf are here.(below)

1. egrep cgi lighttpd.conf
   "mod_fastcgi",
   "mod_cgi",
   alias.url = ( "/cgi-bin/" => "/usr/local/www/cgi-bin/" )
2. .php, .pl, .fcgi are most often handled by mod_fastcgi or mod_cgi
   static-file.exclude-extensions = ( ".php", ".pl", ".fcgi", "qmailadmin" )
   1. fastcgi module

1. read fastcgi.txt for more info
2. for PHP don't forget to set cgi.fix_pathinfo = 1 in the php.ini
   fastcgi.server = ( ".php" =>
   "socket" => "/var/run/lighttpd/php-fastcgi.socket",
   "bin-path" => "/usr/local/bin/php-cgi",
   cgi.assign = ( ".pl" => "/usr/bin/perl",
   ".cgi" => "/usr/bin/perl",
   "/cgi-bin" => "/usr/local/www/cgi-bin/qmailadmin",
   "/qmailadmin" => "/usr/local/www/cgi-bin/qmailadmin")

with this config options, when i tried to access t? "qmailadmin" i am getting this error, in error log of server.
2009-04-22 13:04:12: (mod_cgi.c.1244) cleaning up CGI: process died with signal 6
thanks any way...