By default, the dial-by-name function in a Cisco CUE aef script will not announce users if there are more than 3 duplicates.
For example, if there are 4 "Smith"s in your user list and someone dials "SMI" in your auto attendant dial by name option, they will hear "Continue to dial the name". They will need to dial the complete "SMITH" last name and at least a digit of the first, narrowing the name duplications to 3 or less before CUE gives them a list to choose from.
This is not too much of a problem unless the company is run by the "Smiegenburgerskis", and 4 of them work there.
See the "Name To User" control properties, under your dial-by-name tree in CUE Editor. You can raise the "Announce when number of matches less than:" value to a maximum of 6.
This way, a user dials "SMI" and is given a list of the 5 or less matches.