PHP install on IIS - getting CGI Timeout

[shadow_rei]

I manually installed PHP 5.2.0 on Windows XP Pro with IIS 5.1.  When I try to view any php page in a browser, I get the following error:

[quote]CGI Timeout
The specified CGI application exceeded the allowed time for processing. The server has deleted the process.[/quote]

The IUSR account has access to the appropriate php files.  I mapped .php to c:\php\php.exe in IIS.  I tried adding "%s %S" to the mapping and instead of getting a timeout, my phpinfo page tried to download as a file, and my test php page gave the following error:

[quote]CGI Error
The specified CGI application misbehaved by not returning a complete set of HTTP headers. The headers it did return are:[/quote]

When I run php on the command line (e.g. "php c:\Inetpub\wwwroot\phpinfo.php"), I get the correct response, so I'm guessing this is a problem with IIS settings.

Does anyone know what might be causing this?

Thanks in advance!