Your welcome.
The auto complete feature uses a list of the last 29 names you've emailed to. This list includes people you reply to, so a name can get there even though you didn't actually type the name into an email. This list is kept in the registry. If you start typing a name and it offers the wrong name, just keep typing the correct name. If it is one of the last 29, it should offer it when it is the only (or at least the most recent of the possibilities) choice left.
Gary