Invalid Namespace Error While Login Report Manager

I am using Custom Security Extension DLL for implementing Forms Authentication in Reporting Service 2005. While Login I am getting an "Invalid Namespace" error. After debugging it, i found below lines in the AuthenticationUtilities.cs page of the Custom DLL which is giving error.

const string WmiNamespace = @"\localhost
ootMicrosoftSqlServerReportingServicesv8";
const string WmiRSClass = @"MSReportServerReportManager_ConfigurationSetting";

scope = new ManagementScope(WmiNamespace);

// Connect to the Reporting Services namespace.
scope.Connect(); //This is the line where the error is coming. It is trying to conenct WMI provider

Can anyone help me in figuring out What is wrong with the WmiNamespace ???????


Thanks,
Akash