Outlook problem after profile rename

[JAR]

One of our clients is in the process of renaming their user logons from the
format (e-mail address removed) to (e-mail address removed)

They are renaming the users logon name, their profile folder and their home
folders and updating the profile tab in active directory to reflect the
changes. It appears that most things work OK but they are having problems
with some users in that Outlook runs the wizard to create a new profile. This
is not convenient as most end users do not what settings to enter.

Is there any reason why new Outlook profiles are created for some users and
not others ?

Thanks