As a workaround you could set your local computer or routers nameservers to ns1.dreamhost.com, ns1.dreamhost.com, ns1.dreamhost.com... clear your DNS cache and you should be able to access the admin url on the dreamhost site again. You could also modify your local HOSTS file as detailed in this wiki article, but that requires you know the IP address.
Your really in the same situation DNS wise as someone that is setting up a new site on dreamhost and wants to work on it before moving the sites DNS to dreamhost.
Here are some nslookups that might be helpful to you. Including the IP you would need to use if you wanted to use the HOSTS file method.
$ nslookup demolaysc.org.br ns1.dreamhost.com