Error:

	...
	fcgi-server re-enabled:  0 /var/run/lighttpd/php-fastcgi.socket
	backend is overloaded; we'll disable it for 1 seconds and send the request to another backend instead: reconnects: 0 load: 1391
	...

Fix:

	fastcgi.server  = ( ".php" =>
				( "localhost" =>
				  (
				     "socket" => "/var/run/lighttpd/php-fastcgi.socket" + var.PID,
				     "bin-path" => "/usr/bin/php-cgi",
				     "max-procs" => 10,
				     "bin-environment" => (
					"PHP_FCGI_CHILDREN" => "20",
					"PHP_FCGI_MAX_REQUESTS" => "5000" ),     
				  )
				)
			  )

System details:

• Distribution - CentOS release 5.5 (Final)
• Kernel - Linux 2.6.18-194.26.1.el5 #1 SMP i686 i686 i386 GNU/Linux
• CPU - Intel(R) Xeon(TM) CPU 3.06GHz 512KB Cache
• Memory - 3115824 kB (3GB)
• Lighttpd - lighttpd-1.4.28-1.el5.rf
• FastCGI - lighttpd-fastcgi-1.4.28-1.el5.rf
• PHP - php-5.1.6-27.el5_5.3

Let me know if this fix yours too. Leave it on the comment section below. Thanks!