Un like sql 2000 FTS on SQL 2005 is a much more capable beast, but that also means it is much more capable of taking all the resources. You need to configure you SQL and Full text service to work together.

In your situation it would suggest that the correct ifilters are not installed, this is possibly due to the way that iFilters are registered in SQL 2005.

See http://www.simple-talk.com/sql/learn-sql-server/sql-server-full-text-search-language-features/

As for the DAC. it is enabled but not for remote connections, and there is a valid reason. You can only have one DAC, if someone is connected remotely with the DAC, you have no way of findging out who is connected. Which measn when your server is being screwed you can't connect.