LDAP Authentication and Speed Issue

We are having problems authenticating to our LDAP server. We are running drupal 4.7 on a linux server and ldap is running windows 2000 active directory. Currently, we have an established connection to the ldap server, but when a user tries to login, it takes over 2 minutes to come back w/ the failed message and we don't see a login request coming from the server to the ldap.

We were getting repeated bind failures and user errors. This was reconciled when we recreated a non-anon user for the LDAP. The old one stopped working. Since we stopped getting bind failures the site has slowed down significantly (almost like a dialup connection) since we established a connection to the ldap server. We've determined that our ldap server isn't causing the problem because its response time is normal. In addition we can log into the LDAP using the non-anonymous user from another site and get full access to the LDAP. Here are our settings in the ldapauth:

LDAP server: is correct.
Ldap port - 389
Login procedure - drupal's own database. If it fails, will look on the ldap directory
Base DNs:LDAP://servername.corp.companyname.com/dc=corp,dc=companyname,dc=com
UserName attribute:sAMAccountName

We also have DN for non-anonymous search setup that is functionally normally.

We need help to determine why we are not sending the authentication request to the LDAP server and why our system has slowed down completely since we binded to the ldap server?