When I add info to a contact it makes a new entry in my "Address Book".
Some have multiple entries of the type "SMTP" and others have the type "FAX" as well.
Why does it give me another (new) contact instead of just saving the original one with the changes?
Outlook actually did save the changes to the original contact and only a single contact will exist in your Contacts folder.
The difference you see when looking at the Address Book is because the Address Book expands all contact methods for each contact so you can specifically select that method of contacting.
Multiple E-mail addresses per contact and Fax numbers
If you add multiple email addresses for a single contact, you’ll get multiple “smtp” type entries for that contact in the Address Book. When you add Business Fax, Home Fax or Other Fax details to a contact, you’ll get a “fax” type entry as well.
Hiding Fax numbers in the Address Book
If you do not want to display the fax numbers in the Address Book, you can invalidate the fax numbers by putting a letter in front of the fax number such as "F" or simply "Fax".
If you want to do that for your entire Contacts folder and want Outlook to automatically pre-fix fax numbers with “Fax”, you can use the add-in Hide Fax Numbers from SperrySoftware.
If you decide to order use BH93RF24 to get a discount.
Note: The “E-mail Type” column is shown in the Address Book of Outlook 2003 and previous. Outlook 2007 no longer has that column but still shows the fax type indication behind the Display Name of the additional entry in the Address Book.