that error means it wasn't able to attach to the running DOH instance. Try logging in as the account that installed Unity (i.e. the account that's associated with the AVxxx services in the SCM), this always works. Other accounts can work but this one will always work.
Don't worry... I'm working on versions of several of these tools (BulkEdit, dbWalker etc...) that don't talk to the DOH at all any more but go straight to SQL for 3.x and these types of rights issues will go away (or at least get real simple... you have access to our database in SQL, you're good to go).
Jeff Lindborg
Unity Technical Lead/Answer Monkey
Cisco Systems
lindborg@cisco.com
http://www.AnswerMonkey.net (new page for Unity support tools and scripts)