Contact Not Creating A New Contact If There is A Similar Name In The System

We need some help on this. When creating a new company contact and if there is already another contact with the same name in the system, it looks like it saves the new contact, but it does not. We can add a middle initial to the first name and it will create the contact, but then we have to go in and edit the middle initial out. This started when we up graded to the most recent edition. It does work if there is no other contact with the same name in the system.