Hi Bryan,
This behaviour changed in the release of Unity 4.2 and carries over to 5.x this may seem cumbersome for some users, but is really a good thing when you think about it;
Improved Security for Accessing Cisco Unity
To enhance security, the Cisco Unity conversation no longer indicates whether the ID or password is invalid when subscribers log on by phone. Instead, when a subscriber enters an incorrect ID and/or password, Cisco Unity merely indicates that the subscriber entered an invalid combination, and then prompts the subscriber to re-enter both the ID and the password. In this way, it is not clear to an unauthorized user which part of the credentials is valid.
In addition, Cisco Unity no longer applies the prompt speed and volume that is specified for an individual subscriber until the subscriber enters both a valid ID and a valid password.
http://www.cisco.com/en/US/docs/voice_ip_comm/unity/42/release/notes/cu421rn.html#wp340106
Hope this helps!
Rob
