I installed PHP3 under NT4 SP5, running IIS4, and everything works fine, mapping all .php to php.exe.  However, I installed PHP4 and everything fails.  

If I leave my set up as it was, i.e. php files map to php.exe I get the following error:

CGI Error
The specified CGI application misbehaved by not returning a complete set of HTTP headers. The headers it did return are:
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However, if I set up my an ISAPI filter, and map all .php files to the .dll, I get this error first:
HTTP 500 error
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and then this error:
Invalid access to memory location. 
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Strangely, from dos prompt if I type php.exe I can type in code and it returns a valid response.  Doesn't seem to recognise function session_start() so I wonder if it is using php3 ?????

I have set up a .ini file, have disabled all modules, etc. etc.


Could someone please help ???

Matthew o