I had the same problem and did as other guests here suggested... and it worked for my 8700G.

The problem is definitely the outlook contacts where either the First name or Last Name are missing, or have strange characters. If you don't want to get crazy by going through all your contacts, you can go in Outlook, personalize the view by inserting First name and Last Name as fields, then click the Last Name column header and sort Ascending. Then make sure there are no Contacts with a blank Last Name or First Name field.

Gianluca, Dublin