Use PHP.EXE rather than the ISAPI filter/extension. I have encountered the same problems trying to get IIS to run with it. ISAPI loads in-process to INETINFO (IIS) and is the fastest way to extend the web server. Unfortunately, I've never seen a correctly working version of PHP's ISAPI supported. So my recommendation is to use PHP.EXE (CGI version). Since it is so small, it's image is cached by NT and is therefore still very fast.
Dave
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