403 forbidden all *.axd files - aragh - iis-7.5

Question

I can run the application on my development machine.
When I go to publish it to my production machine, it does not work. Says that the .axd files are forbidden.
Any ideas? I'm getting so frustrated!
Edit:
As a test, I've changed to be "storage=file;". When I send a request to the server for generating a chart, the chart actually appears in my folder - it just doesn't get sent back to the browser in the request.
ARAGH! What is going on!?!?!
Added web.config
<?xml version="1.0"?>
<configuration>
<appSettings>
<add key="ChartImageHandler" value="storage=memory;"/>
</appSettings>
<connectionStrings>
<add name="VS265178_1ConnectionString" connectionString="Data Source="HIDDEN"/>
</connectionStrings>
<system.web>
<httpHandlers>
<add path="ChartImg.axd" verb="GET,HEAD,POST" type="System.Web.UI.DataVisualization.Charting.ChartHttpHandler, System.Web.DataVisualization, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"
validate="false" />
</httpHandlers>
<compilation debug="true" targetFramework="4.0">
<assemblies>
<add assembly="System.Web.DataVisualization, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
<add assembly="System.ComponentModel.DataAnnotations, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
<add assembly="System.Data.Linq, Version=4.0.0.0, Culture=neutral, PublicKeyToken=B77A5C561934E089"/>
<add assembly="System.Data.Entity, Version=4.0.0.0, Culture=neutral, PublicKeyToken=B77A5C561934E089"/>
</assemblies>
</compilation>
<authentication mode="Forms">
<forms loginUrl="Login.aspx" name=".CFCASPXFORMSAUTH" defaultUrl="Default.aspx"/>
</authentication>
<authorization>
<deny users="?"/>
</authorization>
<machineKey validationKey="HIDDEN" decryptionKey="HIDDEN" validation="SHA1"/>
<!-- Custom Membership Provider Configuration -->
<membership defaultProvider="CFMembershipProvider" userIsOnlineTimeWindow="15">
<providers>
<clear/>
<add name="CFMembershipProvider" passwordFormat="Clear" type="HIDDEN" enablePasswordRetrieval="false" enablePasswordReset="true" requiresQuestionAndAnswer="false" writeExceptionsToEventLog="false"/>
</providers>
</membership>
<profile defaultProvider="CFProfileProvider">
<providers>
<add name="CFProfileProvider" type="HIDDEN"/>
</providers>
</profile>
<pages>
<controls>
<add tagPrefix="asp" namespace="System.Web.UI.DataVisualization.Charting" assembly="System.Web.DataVisualization, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
</controls>
</pages>
</system.web>
<system.webServer>
<validation validateIntegratedModeConfiguration="false"/>
<handlers>
<remove name="ChartImageHandler"/>
<add name="ChartImageHandler" preCondition="integratedMode" verb="GET,HEAD" path="ChartImg.axd" type="System.Web.UI.DataVisualization.Charting.ChartHttpHandler, System.Web.DataVisualization, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
</handlers>
</system.webServer>
</configuration>

Answer 1

URL rewrites on the web site are inherited by all child applications. One solution is to add this to your application web.config:
<system.webServer>
<rewrite>
<rules>
<!-- remove parent rewrite rules -->
<clear/>
</rules>
</rewrite>
</system.webServer>

Answer 2

So the answer.
URL Rewrites are a killer.
I had a wordpress installation on a web application which was above the application I was having problems with. The wordpress installation was actually doing rewrites and because it wasn't a file or directory (wordpress default) it was rewriting any request that didn't have a physical corresponding file or folder.
If you're getting random errors, and you're using sub applications - look at the REWRITES!