Adding members to a group not working by selecting last names

JerryL

I'm working on some labs using groups. In the users that I've created it does not find any users by the last name, but if I type in the first name, the users show up. For example; I've created (with the caps in place) Mike GREEN, Jo GREEN, Bill GREEN, Jo BROWN, Pete SMITH. If select ADD and type in GREEN, no users are found, but if I type in Jo, I get both Jo GREEN and Jo BROWN.

Does anyone have any idea why it won't work with typing in the last name. I've tried with and without caps and also the same thing is in both ADAC an ADUC.

Thanks.