PHP Execution -- very baffled

[phpknight]

This problem is just killing me.  I have a site where scripts sometimes take .1 seconds to run and sometimes take 25 seconds.  I know the latter from email, but the scripts are usually fast for me. 

 

Here is a list of what has been checked.  Anybody who is an expert in this sort of thing, I would appreciate help. 

 

Queries: I check every query time.  mySQL is always under 2% of the total time.

Site Traffic: I have a dedicated server for a small site--almost no load.

Images: Load on the client.  Not an issue.

Bad code: I seriously do not think any coding issue could do this.  Plus, bad code is always bad.

 

I email myself when a script takes too long.  The SAME script with the SAME query and loop will spend 10 seconds in the sidebar.  Twenty minutes later, it is 10 seconds in the body.  I cannot pinpoint this no matter what I do.

 

Has anybody experienced anything like this, and if so, what was the solution?

[adam_]

Hi

 

Are you sure you are not running any intensive scripts on the server? or more importantly, nobody else is?

 

Also have you checked this from multiple computers?

 

Adam

[phpknight]

Yes, and yes.  It is my server (managed), so it is only my small site.  I just can't figure it out.  The server should be able to easily handle a site 100x what mine is.