Change contacts sort in "File as" for all contacts 2007

I have recently moved from Lotus Notes to Outlook 2007 at work (thank
goodness!!). In the migration all my contacts and mail was migrated across to
Outlook with no real problems. he only issue I have is that I would like to
sort all my Contacts by "Last Name, First name". When I view under Outlook
data Files in the "File as" column, it shows that the names have all been
imported as "first last".

If I change back to address card view and open a contact, I see there is a
way to change it to "last, first" but it is a painful way to change each
contact manually. Is there any easy way to change the complete list in a
single operation?

I have tried changing the format in Tools accounts and under Options to
"last, First", but that hasn't helped. It may have something to do with the
way the contcts were imported. Any help would be appeciated. Thanks