Wubi display logon name can lead to confusion

Wubi defaults the Ubuntu username to the Windows user name (except all in lower case) and it defaults the Display name to the Windows user name. e.g. for a windows user name John, Wubi will pick an ubuntu username of
"john". At the login prompt Ubuntu displays "John".

If you choose a different ubuntu username e.g. frank, it will still display "John" at login.

This confuses some people and they forget that they added a different username "frank" and frank's password and start entering their Windows password. Or they assume there is some special Wubi default password.

This is not a serious bug - maybe wishlist - but I think it would be nice if Wubi noticed when the user name is changed and derives a new display name from it. e.g. "Frank" or even just "frank".