Adding a 2003 DC into a 2000 Domain

About a month ago I added a 2003 member server to my domain.  The domain already had 2 other 2003 member servers.  One of which is running exchange 2003.   I ran the forestprep and domainprep before installing Exchange 2003.  The member server is DC1.  After a week of no problems with this server in the domain I promoted it to a DC.  It is also running DHCP and DNS.  I transfered all the FSMO roles over to it from one of 2 2000 DC's.  The roles were split between the 2 2000 DC's.  I set it up as the Authoritive time server as well.  The 2000 DC called ADMIN was the DHCP server.  I stopped DHCP on it.  Most of the machines in the network switched over without a problem.  A few reported duplicate IP's on the network but a reboot corrected this.  I also found some "Bad Address" listings in the DHCP table.  I removed these as well.  All three DC's were Global Catalog servers as well.  After 2 weeks without any other problems.  I decided to turn off ADMIN to see if any problems would arise.  I am not sure if this was a good or bad idea, but it seemed a good way to test the 2003 DC.  2 of my 2003 member servers had errors in the event log stating they could not find a DC to authenticate with so no group policy would be loaded.  I rebooted them and they took at least ten minutes to get past the applying group policy window, right before the CTRL+ALT+DEL window pops up.   I turned ADMIN back on because I was unsure if this had any relation to that DC being off.  All the errors in the event logs of the 2 2003 servers went away.  ADMIN was the first DC in this domain.  I am not sure if more needs to be done besides transfering the FSMO roles and the global catalog.  Another strange thing I noticed was when i try to change a logon script in the Netlogon folder of DC1, The change would not replicate to the other 2 DC's.  Today I was investigating this and I noticed that from DC1 I can view the NETLOGON folder on ADMIN and the other DC, BACKUP, but i cannot even edit the scripts.  If I right click on a script and click edit, I get an error stating a permissions error.  There are no errors in the Replication log and other things seem to be replicating perfect.  User account creation, I unchecked ADMIN as a Catalog server and that replicated the change on the other 2 DC's.  I'm not sure whats going on though.  Not sure if I missed a step.  Any suggestions are greatly appreciated and I can elaborate further on anything I've posted here so far.  I apologize in advance for the how scattered this post is as my thoughts were trying to document each thing i've noticed.  Thanks again,