http error 500.19 - Internal server error - asp.net

Question

I am trying to get an application (that I didn't develop) running on a windows 2008 r2 64-bit server running IIS 7.5.
I am getting the above stated error - here are more details -
The requested page cannot be accessed because the related configuration data for the page is invalid
Error Code 0x8007007e
I know that the server can access the web.config, because if I make changes to it, the error code changes.
I also know that it is a correct web.config, because it is running successfully on a different server with the same file.
Does anyone have any idea what might be causing this. The error message I am getting really doesn't tell me anything.
I have tried using FailedRequestTracing, but either I don't know how to read those logs or there is no more information there. There are also no errors in the event logs on the server.
Where else can I look to get a better idea of what is happening?
Thanks for any thoughts....
EDIT - Here is the web.config. As I said earlier, it is strange that it is working on another server. I checked to ensure are referenced assemblies are available (as according to the page here, it appear that may be the problem) in the gac.
<?xml version="1.0" encoding="UTF-8"?>
<configuration>
<appSettings>
<add key="ChartImageHandler" value="storage=file;timeout=20;dir=c:\temp\;deleteAfterServicing=false;" />
</appSettings>
<connectionStrings>
<!-- removed for this post -->
</connectionStrings>
<system.data>
<DbProviderFactories>
<!--<add name="IBM Informix .NET Data Provider 3.0.0" invariant="IBM.Data.Informix.3.0.0" description="IBM Informix Data Provider 3.0.0 for .NET Framework 2.0" type="IBM.Data.Informix.IfxFactory, IBM.Data.Informix.3.0.0, Version=3.0.0.2, Culture=neutral, PublicKeyToken=7c307b91aa13d208"/>-->
</DbProviderFactories>
</system.data>
<system.web>
<httpRuntime maxRequestLength="8192" />
<customErrors mode="Off" />
<sessionState timeout="360" />
<pages controlRenderingCompatibilityVersion="3.5" clientIDMode="AutoID">
<namespaces>
<clear />
</namespaces>
<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>
<!--
Set compilation debug="true" to insert debugging
symbols into the compiled page. Because this
affects performance, set this value to true only
during development.
-->
<compilation debug="true" targetFramework="4.0">
<assemblies>
<add assembly="System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=B77A5C561934E089" /></assemblies></compilation>
<httpHandlers>
<add path="ChartImg.axd" verb="GET,HEAD" type="System.Web.UI.DataVisualization.Charting.ChartHttpHandler, System.Web.DataVisualization, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" validate="false" />
</httpHandlers>
</system.web>
<system.web.extensions>
<scripting>
<webServices>
<jsonSerialization maxJsonLength="5000000" />
</webServices>
</scripting>
</system.web.extensions>
<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>
<defaultDocument>
<files>
<add value="index.aspx" />
</files>
</defaultDocument>
<tracing>
<traceFailedRequests>
<add path="*.aspx">
<traceAreas>
<add provider="ASP" verbosity="Verbose" />
<add provider="ASPNET" areas="Infrastructure,Module,Page,AppServices" verbosity="Verbose" />
<add provider="ISAPI Extension" verbosity="Verbose" />
<add provider="WWW Server" areas="Authentication,Security,Filter,StaticFile,CGI,Compression,Cache,RequestNotifications,Module,FastCGI" verbosity="Verbose" />
</traceAreas>
<failureDefinitions timeTaken="00:00:00" statusCodes="400-600" />
</add>
</traceFailedRequests>
</tracing>
</system.webServer>
</configuration>

Answer 1

It's a bit cheaty, but Microsoft has a page specifically about this problem ... and myriad suggestions for fixing it. Have you gone through it yet?
http://support.microsoft.com/kb/942055

Answer 2

Try this http://windowslivehelp.com/thread.aspx?threadid=3dd85141-a45d-44d9-a94c-3c7d13cfcd5c

Answer 3

I was able to get past this error by disabling compression that is applied by having wsus on the server.
See details here.
Thanks for everyone's help.