PHP memory problems

Hello, I'm using PHP 4.0.6 and have the following (very annoying) problem: Running a complex web application, after some time of use, I got the 'memory limit exceeded' message, in different points of my application. Waiting some time sometimes solves the problem. I believe the fault is in the memory allocation/deallocation routines, because I do a lot of string concatenation and know this operation can be a real pain for memory management code. The question is how does PHP deal with memory? i mean, does it have a unique memory pool for every page hit? Is the 8 Mb limit for every page hit? Is it possible that the memory reclaim code is causing such a behaviour? is there a way to force a garbage collection run? Any hint/though? Thanks Cris -- Cristiano Verondini http://noway.ing.unibo.it [Due cose sono infinite: l'universo e la stupidità umana, e non sono sicuro della prima]