PHP4 & IIS 5...Server hangs after a few pages have been requested

I've Installed PHP 4 (ISAPI Version) under II5 on Windows 2000 Server.   For the first few page requests it works fine, but after a while (or after an error message has been returned by a dodgy script) all IIS virtual servers go really slow and often hang completely. The rest of the machine runs slow aswell and it is painful just getting to the command line or MMC to kill the w3svc services. If I remove the PHP ISAPI settings from the "ISAPI Filters" & "Home Directory"->"Configuration" tabs in MMC then the all virtual web servers work fine without PHP.   I installed PHP exactly as described in the instructions. I have also setup the latest version Apache on the same machine and it runs PHP fine.   Does anyone know what's causing this?   Matt matthew@ralston.net < www.mralston.co.uk />     ***************************************************************************************** This email contains information which may be confidential or privileged. T he information is intended solely for the use of the individual or entityn amed above. If you are not the intended recipient, be aware that any disclosure, copying, distribution or use of the contents of this information is prohibited. If you have received this electronic transmission in error, please notify us on 0151-423-1391 or by electronic mail at postmaster@haltoncollege.ac.uk immediately. Any opinions expressed are those of the author, not Halton College of FE and HE. This email does not constitute either offer ora cceptance of any contractually binding agreement. Such offer or acceptance must be communicated in writing. ****************************************************************************************