Funny memory leak problem.

Hi, I am using PHP4-B2, together with Apache 1.3.9 (Ben-SSL) and occassionally get httpd processes all of a sudden taking up 30% of the memory (a bit of a bummer). The load on the server is not big, and with a MaxRequestsPerChild set to something like 25 there are no problems, but I would still like to know what actually causes it. The script does quite a big of MySQL quering, occasionally it'll exec() something, and it does not mysql_free_result() it's data. I thought PHP (or the new Zend engine) would always at the end of the script deallocate all of the memory - 100% effective garbage collecting. But every now and then I will see an httpd process taking up more than 30% of memory (they usually sit at 1.7 - 2.0 %) - and even with a MaxRequestsPerChild of 25 - so whatever it is it is leaking like crazy :-) It's not that I don't want to clean up the script and do proper garbage collecting myself, but I was under the impression you wouldn't have to worry about memory in the first place. Can someone give me an example of a script that will hog lots of memory in a short time, and will make the httpd process keep that memory while the connection is already lost? For educational purposes :-)) On a sidenote, the session_handling -> isn't it supposed to clean up it's temp files in /tmp? I know there is this var that holds the probability for garbage collecting, and I've played with that but I've never seen PHP actually take care of the /tmp files it used. (Users are not forced to log in and out, I just want the session to expire after say a day, and the associated /tmp/$phpsession_id() file deleted. Hope I'm not missing a bunch of obvious bits :-) Thanks for any input! Dennis