Why doesn't LDAP Priority and Weight change entry in the DNS?

We have two Windows 2008 servers that are Active Directory Domain Controllers.  They seem to be configured properly, and are talking to each other.

I want one of the domain controllers to authenticate all of the logins because it's a more powerful box.  I want the second DC to take over if the first goes down.

I went into the Registry on the old machine, and created two 32 bit Dword registry keys as follows:

HKLM\SYSTEM\CurrentControlSet\Services\Netlogon\Parameters.

LdapSrvPriority

and

LdapSrvWeight.

Set these to 5 and 150.  Assumed the default on the faster server was 0 and 100, thus making the newer server the default choice for logon authentication.

Rebooted server.   Checked DNS, and it still is reporting 0 100 for both servers, and doing an

echo %LOGONSERVER% on various workstations seems to show that authentication is round
robining between both servers.  
Why aren't these settings sticking?  And why weren't they in the registry when I started?
Thanks