lighttpd forum lighty > Gentoo + Lighttpd + fastCGI using codeigniter very slow

Hi!

I'm doing some migration from servers to another, so I used the same 
configuration as before which is lighttpd with fast-cgi under gentoo and 
it should run my codeigniter application that I developed recently.

But after all stuff set properly, I ran the server and at the beginning 
everything runs fast and fine (it's basically an administration panel) 
after log out it starts to slow down and takes time to respond while my 
old server worked fast everytime! I took the same configuration files 
but the softs version a probably not the same!

Anyway I think there is something wrong with the cgi and the session 
that slows the requests back and forth.

Can someone help me to figure it out the issue please?

there is my soft versions :
- www-servers/lighttpd-1.4.20
- dev-lang/php-5.2.6-r7

thanks for you anwser!
Sry for my broken english....