Lighttpd problem

Hi please help, sudden problem. (Without modification)

My server ~ 3-4 days ago, daily 4-5x timeout problem (slow loading my website).
Always the problem occurs every 4 hours!!! (No cronjob)
5500-28000 ms loading time 2-3 minutes and after resolves.
3-4 days before anything about not set the server! I do not touch it!

I watched all Logs, did not find error!
Today again lighttpd reinstalled, did not solve the problem...

Server:
Debian lenny
Mysql+php5+Lighttpd. 1.4.9

Waiting all ideas what can cause, Thanks.

Well, what is the page? Is it a static webpage or something CGI?

Cgi. (fastcgi= php5+lighttpd)

I suspect the contents of this CGI script have a lot more to do with these outages than the web server.

Thanks, What to see / check?

Without seeing the program, we really can't tell what's wrong with it. We can't even make a wild guess at this point.

Maybe Reinstall php5-cgi?

I really doubt it.

I'm not withholding a magic do-everything fix from you. We really don't have enough information to diagnose your problem yet. There's no single problem in particular that causes things to 'freeze'. Please show us this program, or at least tell us more about what it is.

Tested different php+html.
Simple Php: "<? echo mt_rand(1,10000);?>" -> 25000 ms
Hrml: now OK. (200ms) Sometime good, Sometime bad...

...CGI problem may be?

what kind config file copied? and diagnostic?

More information:
It do four times a day on the dot. (2-3 minutes slow)
Ftp speed OK, only "web" slow. (20000-30000 ms loading time)

the entire webserver, or a specific page upon it?

What does top look like when the webserver's frozen?

Yes, entire webserver!

No transition, normal speed/very slow vary. Usually slow...<-It is 2-3 minutes, after good(normal) speed.