We recently upgraded our webserver from w2k3 + iis6 to w2k8 + iis7.  After that I upgraded DNN from 4.7.x to 4.8.2 and the latest version of the AD provider.  Since then the autologin that was working before the DNN/AD upgrade is not longer working for windows users.

On the Admin->Authentication setting page, I get the all OK with the settings, but below the auto-login text area is the following error:
Error: is currently unavailable.
DotNetNuke.Services.Exceptions.ModuleLoadException: Access is denied. ---> System.Runtime.InteropServices.COMException (0x80070005): Access is denied. at System.DirectoryServices.DirectoryEntry.Bind(Boolean throwIfFail) at System.DirectoryServices.DirectoryEntry.Bind() at System.DirectoryServices.DirectoryEntry.get_IsContainer() at System.DirectoryServices.DirectoryEntries.ChildEnumerator..ctor(DirectoryEntry container) at System.DirectoryServices.DirectoryEntries.GetEnumerator() at DotNetNuke.Authentication.ActiveDirectory.Settings.CheckPipelineMode() at DotNetNuke.Authentication.ActiveDirectory.Settings.Page_Load(Object sender, EventArgs e) --- End of inner exception stack trace ---

I put a link on the front page of DNN that goes directly to ~/DesktopModules/AuthenticationProviders/ActiveDirectory/WindowsSignin.aspx and if anyone clicks that, it logs them in just fine for a while, then they have to click it again.  The forms auth cookies are set to expire every 60 minutes(default).

The line below is uncommented in the <httpModules> section of my web.config.
<add name="Authentication" type="DotNetNuke.Authentication.ActiveDirectory.HttpModules.AuthenticationModule, DotNetNuke.Authentication.ActiveDirectory" />
The WindowsSignin.aspx file is set for WindowsAuthentication and formsAuth(defaulted) with Anon disabled.

My AppPool is running as NetworkService in ClassicMode.
I have uninstalled the AD Provider, made sure everything was gone, then reinstalled it.
I have tried deleting the cookies on my local IE, but it still does not auto-login.

Any ideas on what I'm missing?

It does not appear that DNN is redirecting to the WindowsSignin.aspx when a user hits the site.  That may be the problem right there.  How do I fix that?

Error from the event log in DNN:

ModuleId: -1
ModuleDefId: -1
FriendlyName:
ModuleControlSource:
AssemblyVersion: 04.08.02
PortalID: 0
PortalName: XXX
UserID: 1
UserName: XXX
ActiveTabID: 52
ActiveTabName: Authentication
RawURL: /Admin/Authentication/tabid/52/Default.aspx
AbsoluteURL: /Default.aspx
AbsoluteURLReferrer:
UserAgent: Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.1; .NET CLR 1.1.4322; .NET CLR 2.0.50727; .NET CLR 3.0.04506.30; .NET CLR 3.0.04506.648; .NET CLR 3.5.21022)
DefaultDataProvider: DotNetNuke.Data.SqlDataProvider, DotNetNuke.SqlDataProvider
ExceptionGUID: de057231-46f0-4af9-90ff-919a3390be9c
InnerException: Access is denied.
FileName:
FileLineNumber: 0
FileColumnNumber: 0
Method: System.DirectoryServices.DirectoryEntry.Bind
StackTrace:
Message: DotNetNuke.Services.Exceptions.ModuleLoadException: Access is denied. ---> System.Runtime.InteropServices.COMException (0x80070005): Access is denied. at System.DirectoryServices.DirectoryEntry.Bind(Boolean throwIfFail) at System.DirectoryServices.DirectoryEntry.Bind() at System.DirectoryServices.DirectoryEntry.get_IsContainer() at System.DirectoryServices.DirectoryEntries.ChildEnumerator..ctor(DirectoryEntry container) at System.DirectoryServices.DirectoryEntries.GetEnumerator() at DotNetNuke.Authentication.ActiveDirectory.Settings.CheckPipelineMode() at DotNetNuke.Authentication.ActiveDirectory.Settings.Page_Load(Object sender, EventArgs e) --- End of inner exception stack trace ---
Source:
Server Name: XXX

It's all done in the code but it's looking like a permission issue is preventing it from automatically hitting the page. Do some checking on Failed Request Tracing Rules for IIS 7. Perhaps we can get more information through that.