I haven't been following this thread in detail, but MS Active Directory LDAP is working with my instance of Koha 3.0.1, which is running on Debian Lenny.

My configuration is as follows:

<useldapserver>1</useldapserver>

 <!--LDAP SERVER (optional) -->
<ldapserver id="[server name]"  listenref="[server name]">
 <hostname>[server IP]</hostname>
 <base>[Active Directory Distinguished Name of Domain]</base>
 <user>[Active Directory Distinguished Name of AT admin user]</user>
 <pass>[PASSWORD]</pass>
 <replicate>1</replicate>
 <update>1</update>
 <auth_by_bind>1</auth_by_bind>
 <mapping>
                <firstname is="givenname"></firstname>
                <surname is="sn"></surname>
		  <address2 is="physicaldeliveryofficename"></address2>
                <userid is="samaccountname"></userid>
                <password is="userpassword"></password>
		  <email is="mail"></email>
		  <phonepro is="telephonenumber"></phonepro>
 </mapping>
</ldapserver>

Hope this helps.