You'll want to get your hands on 2.4.6 to resolve this...
we changed the subscriber sign in conversation to hang up if the first digit it hears is "*" and to return to the opening greeting if the first digit it hears is "#". The problem we were dealing with in the field was there was not good way to get Unity to hang up if, for instance, you tried to conference someone in, their phone was busy/rna and it forwarded to Unity. You can't hang up the line without losing your other party and you couldn't get Unity to shut up easily.
in the new scheme, no matter where you are in the conversation (as an outside caller or a subscriber) hitting "*" repeatedly will force Unity to terminate (usually 2 or 3 *s will do it unless you're deep in some optional menu as a subscriber).
Unfortunately 2.4.5 missed the "#" thing so there's no easy way to get back to the opening greeting if you find yourself at the subscriber sign in conversation. 2.4.6 fixed this.
Jeff Lindborg
Unity Product Architect/Answer Monkey
Cisco Systems
lindborg@cisco.com
http://www.AnswerMonkey.net (new page for Unity support tools and scripts)