unhandled exception

Trying to run on a hosted service and am getting this message.  Is it due to a lack of trust level?  If not, how would this be resolved?

Thanks


 This server variable cannot be modified during request execution.
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Full 

Exception Details: System.Web.HttpException: This server variable cannot be modified during request execution.

Source Error:

An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.

Stack Trace:

[HttpException (0x80004005): This server variable cannot be modified during request execution.]
   System.Web.HttpServerVarsCollection.SetServerVariableManagedOnly(String name, String value) +2672713
   System.Web.HttpServerVarsCollection.SynchronizeServerVariable(String name, String value) +28
   System.Web.HttpRequest.SynchronizeServerVariable(String name, String value) +112
   System.Web.Hosting.IIS7WorkerRequest.GetServerVarChanges(HttpContext ctx) +388
   System.Web.Hosting.IIS7WorkerRequest.SynchronizeVariables(HttpContext context) +30
   System.Web.HttpRuntime.ProcessRequestNotificationPrivate(IIS7WorkerRequest wr, HttpContext context) +477

Update:
This seems to only occur when using the AD/ integrated logon.  Using windows 08 and iis7.

This may be caused by ISAPI filters or HttpModules, please check your IIS configuration.

This is a MS bug: When we subscribe to Begun request on Http Module and SF_NOTIFY_AUTHENTICATION  in ISAPI filter in Integrated pipeline mode. It has no solution at present.