When using the Windows Login option and typing my username as domain\username and my Active Directory password, I recieve this error:

A critical error has occurred. This Membership Provider has not been configured to support password retrieval.

If I type an incorrect password, then it recognizes that the password is incorrect and shows a login failed error.   When the password is typed correctly and I should be logged in, I see the above error instead.

Any ideas why I would see this error and/or how to fix it?

This is the full error in the event viewer.
===========================

AssemblyVersion: 04.06.02
PortalID: 0
PortalName: [removed ]
UserID: -1
UserName:
ActiveTabID: 66
ActiveTabName: Contact
RawURL: /Contact/tabid/66/ctl/Login/Default.aspx?returnurl=%2fContact%2ftabid%2f66%2fDefault.aspx
AbsoluteURL: /Default.aspx
AbsoluteURLReferrer: http://[removed]/Contact/tabid/66/ctl/Login/Default.aspx?returnurl=%2fContact%2ftabid%2f66%2fDefault.aspx
UserAgent: Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.0; SLCC1; .NET CLR 2.0.50727; .NET CLR 3.0.04506; InfoPath.2; .NET CLR 1.1.4322)
DefaultDataProvider: DotNetNuke.Data.SqlDataProvider, DotNetNuke.SqlDataProvider
ExceptionGUID: bcbcf5f6-acef-40d0-b70b-9aeb86393b07
InnerException: This Membership Provider has not been configured to support password retrieval.
FileName:
FileLineNumber: 0
FileColumnNumber: 0
Method: System.Web.Security.SqlMembershipProvider.GetPassword
StackTrace:
Message: DotNetNuke.Services.Exceptions.PageLoadException: This Membership Provider has not been configured to support password retrieval. ---> System.NotSupportedException: This Membership Provider has not been configured to support password retrieval. at System.Web.Security.SqlMembershipProvider.GetPassword(String username, String passwordAnswer) at System.Web.Security.MembershipUser.GetPassword() at DotNetNuke.Security.Membership.AspNetMembershipProvider.ChangePassword(UserInfo user, String oldPassword, String newPassword) at DotNetNuke.Entities.Users.UserController.ChangePassword(UserInfo user, String oldPassword, String newPassword) at DotNetNuke.Authentication.ActiveDirectory.Login.WindowsAuthorization(UserLoginStatus& loginStatus, String IP) at DotNetNuke.Authentication.ActiveDirectory.Login.cmdLogin_Click(Object sender, EventArgs e) at System.Web.UI.WebControls.Button.OnClick(EventArgs e) at System.Web.UI.WebControls.Button.RaisePostBackEvent(String eventArgument) at System.Web.UI.WebControls.Button.System.Web.UI.IPostBackEventHandler.RaisePostBackEvent(String eventArgument) at System.Web.UI.Page.RaisePostBackEvent(IPostBackEventHandler sourceControl, String eventArgument) at System.Web.UI.Page.RaisePostBackEvent(NameValueCollection postData) at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) --- End of inner exception stack trace ---
Source:
Server Name: [ removed ]

It is a parent portal (with a few dozen child portals below it) and is portal 0.  I recently upgraded from 4.6.0., and just installed the AD authentication provider once I realized that our domain logins were no login snycing the passwords.  So far, I haven't gotten it to work. 

The only other changes I can think of that I've made are disabling anonymous access in IIS 6 for the Windows Signin page and commenting out the AD Authentication line in the web.config file to stop users from being automatically redirected to the login page.

This is for a University Faculty website that has different users editing or contributing content, so there are external users with builtin DNN accounts, as well as internal users using Active Directory accounts.

I didn't have any install errors when I installed the AD provider, but I could try uninstalling it and reinstalling it to see if I get the same results?