IIS ignores system.webServer staticContent section

Question

UDPATE

On a whim, I decided to upload the 4 fonts files to an font converter. I converted the fontsfrom ttf to ttf and then tried it. Everything works fine: the Content-Type is set correctly and the X-Powered-By header is removed.
Weird.

---

I am trying to change the mime type (Content Type header) of a .ttf file in web.config on IIS7.

Here is the staticContent section inside <system.webServer />:

<staticContent>
    <remove fileExtension=".ttf" />
    <mimeMap fileExtension=".ttf" mimeType="font/ttf" />
</staticContent>

Even with the above configuration all .ttf files are sent with application/octetstream.

I also have a customHeader section with the following:

<remove name="X-Powered-By" />

which successfully removes the X-Powered-By header for css, png, jpg, gif, ico, .aspx, .htm, .html, shtml, and js files. It does NOT, however, work for .ttf.

Anyone know what I'm doing wrong?

---

My entire web.config just in case:

<?xml version="1.0" encoding="UTF-8"?>
<!-- 
    Note: As an alternative to hand editing this file you can use the 
    web admin tool to configure settings for your application. Use
    the Website->Asp.Net Configuration option in Visual Studio.
    A full list of settings and comments can be found in 
    machine.config.comments usually located in 
    \Windows\Microsoft.Net\Framework\v2.x\Config 
-->
<configuration>

  <system.codedom>
    <compilers>
      <compiler language="c#;cs;csharp" extension=".cs" warningLevel="4" type="Microsoft.CSharp.CSharpCodeProvider, System, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089">
        <providerOption name="CompilerVersion" value="v3.5" />
        <providerOption name="WarnAsError" value="false" />
      </compiler>
    </compilers>
  </system.codedom>
  <!-- 
        The system.webServer section is required for running ASP.NET AJAX under Internet
        Information Services 7.0.  It is not necessary for previous version of IIS.
    -->
  <system.webServer>
    <validation validateIntegratedModeConfiguration="false" />
    <httpProtocol>
      <customHeaders>
        <remove name="X-Powered-By" />
        <add name="X-UA-Compatible" value="chrome=1;IE=edge" />
      </customHeaders>
    </httpProtocol>
    <modules>
      <remove name="Session" />
      <remove name="WindowsAuthentication" />
      <remove name="FormsAuthentication" />
      <remove name="PassportAuthentication" />
      <remove name="RoleManager" />
      <remove name="UrlAuthorization" />
      <remove name="FileAuthorization" />
      <remove name="AnonymousIdentification" />
      <remove name="Profile" />
    </modules>
    <staticContent>
        <remove fileExtension=".ttf" />
        <mimeMap fileExtension=".ttf" mimeType="font/ttf" />
    </staticContent>
  </system.webServer>
  <runtime>
    <assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1" appliesTo="v2.0.50727">
      <dependentAssembly>
        <assemblyIdentity name="System.Web.Extensions" publicKeyToken="31bf3856ad364e35" />
        <bindingRedirect oldVersion="1.0.0.0-1.1.0.0" newVersion="3.5.0.0" />
      </dependentAssembly>
      <dependentAssembly>
        <assemblyIdentity name="System.Web.Extensions.Design" publicKeyToken="31bf3856ad364e35" />
        <bindingRedirect oldVersion="1.0.0.0-1.1.0.0" newVersion="3.5.0.0" />
      </dependentAssembly>
    </assemblyBinding>
  </runtime>
</configuration>