DirectoryServicesCOMException on IIS7 with System.DirectoryServices.AccountManagement but not in dev

The following code works fine on my dev PC but crashes when deployed to the server:

using System.DirectoryServices.AccountManagement;

using (var ctx = new PrincipalContext(ContextType.Domain, domainName))
using (GroupPrincipal grp = GroupPrincipal.FindByIdentity(ctx, IdentityType.Name, groupName))
{
    if (grp == null) return new string[0];

    return grp.GetMembers(true).Select(m => m.SamAccountName).ToArray();
}

The crash is as follows:

[DirectoryServicesCOMException (0x80072020): An operations error occurred.]
   System.DirectoryServices.DirectoryEntry.Bind(Boolean throwIfFail) +439513
   System.DirectoryServices.DirectoryEntry.Bind() +36
   System.DirectoryServices.DirectoryEntry.get_AdsObject() +31
   System.DirectoryServices.PropertyValueCollection.PopulateList() +22
   System.DirectoryServices.PropertyValueCollection..ctor(DirectoryEntry entry, String propertyName) +96
   System.DirectoryServices.PropertyCollection.get_Item(String propertyName) +141
   System.DirectoryServices.AccountManagement.PrincipalContext.DoLDAPDirectoryInitNoContainer() +1134
   System.DirectoryServices.AccountManagement.PrincipalContext.DoDomainInit() +37
   System.DirectoryServices.AccountManagement.PrincipalContext.Initialize() +124
   System.DirectoryServices.AccountManagement.PrincipalContext.get_QueryCtx() +31
   System.DirectoryServices.AccountManagement.Principal.FindByIdentityWithTypeHelper(PrincipalContext context, Type principalType, Nullable`1 identityType, String identityValue, DateTime refDate) +14
   System.DirectoryServices.AccountManagement.Principal.FindByIdentityWithType(PrincipalContext context, Type principalType, IdentityType identityType, String identityValue) +86
   System.DirectoryServices.AccountManagement.GroupPrincipal.FindByIdentity(PrincipalContext context, IdentityType identityType, String identityValue) +29
   WebApp.WebForm1.Test() in C:\MyProject\trunk\WebApp\WebForm1.aspx.cs:30

Scenario:

• IIS7 on domain-joined Windows Server 2008 x64
• ASP.NET 4 intranet application
• All authentication modes off in IIS apart from Integrated Windows Authentication
• App pool configured to run as a domain user

Web.config as follows:

<authentication mode="Windows" />
<authorization>
  <deny users="?"/>
</authorization>
<identity impersonate="true" >

System.Security.Principal.WindowsIdentity.GetCurrent().Name returns my AD username in production correctly, so I think that means impersonation is working correctly.

I was having the similar issue.

I was getting this error only after deployed at webserver, it was working perfect on my machine.

I found that ,at server, in IIS, the Impersonation was remained check with Window Authentication.

and by removing this impersonation in IIS,,, the error gone...