Removing Server version from Response Headers using URL Rewrite

Question

I have used the information from Remove Unwanted HTTP Response Headers to remove IIS server version from Response Headers.

1. Add the Server Variable

2. Create the following outbound rule:

   <rewrite>
    <outboundRules>
     <rule name="Remove Server" patternSyntax="ExactMatch">
      <match serverVariable="RESPONSE_SERVER" pattern=".*" />
      <action type="Rewrite" />
     </rule>
    </outboundRules>
   </rewrite>
   

Though the code works fine and URL Rewrite is removing the server version successfully, the integration of the same is screwing up couple of pages in my legacy classical ASPX website as in:

With URL Rewrite:

fa 7 RepCube 8a | Default Measure: 6b Not Set 4e | Size: 84.28Mb 
b3 65 c1 130 6 FY2014 bd 78 9 Processed 76 6 Actual 76 10 Jan-14 To Dec-14 1 76 Delete

Without URL Rewrite:

RepCube | Default Measure: Not Set | Size: 84.28Mb 
FY2014 Processed Actual 10 Jan-14 To Dec-14 Delete

All the data that is getting generated are from the Classical ASPX page with Server side redirects as in <% tags.

Can you please help me understand what can be the problem with the same?