Using Helicon ISAPI_Rewrite 3 looses form POST data


I have the MODx CMS system installed on IIS6 and am using ISAPI_Rewrite 3 to enable Search Engine Friendly URLs.

The code I have works nicely to rewrite /index.php?id=2 etc. to say /friendly-name.htm.  Issue comes with Form POST data going missing on the login and contact forms.  The forms work correctly when Friendly URLs are disabled.  

The ISAPI_Rewrite 3 logfiles show no errors.

I've asked for help on the MODx Forum but have had no response in 3 days.  The Live HTTP Headers AddOn for Firefox shows the data being posted when a form is submitted but the resulting web page does not see the data.

Can anyone advise what I can do to figure where the POST data is going to and how to ensure it survives the ISAPI_Rewrite Process?

My httpd.ini file is below.



RewriteEngine On
RewriteCompatibility2 On
RepeatLimit 32

# ensure any POST data is available after url is rewritten
RewriteCond %{REQUEST_METHOD} !^POST$ [NC]

#  Block external access to the httpd.ini and httpd.parse.errors files
RewriteRule ^/httpd(?:\.ini|\.parse\.errors).*$ / [NC,F,O]
#  Block external access to the Helper ISAPI Extension
RewriteRule ^.*\.isrwhlp$ / [NC,F,O]

RewriteRule ^/(?!(?:manager|assets)/)(.*)\.html(?:\?(.*))?$ /index.php?q=$1?2&$2: [NC,L,U]

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Steve BinkCommented:
I have very little experience with  Helicon's filter, but my experience with IIS6 and PHP shows the exact same behavior.  The PHP bug is here:

What I found when I looked into it was that IIS6 was mangling and/or removing the header data of the original request.  I'm not sure how this impacts Helicon since the filter could be taking over redirection.  If it allows IIS6 to redirect based on Helicon's decisions, then this issue will affect you in the same manner.  I eventually scrapped the project (an app conversion from LAMP to WIMP) because this issue could not be resolved.

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