Hi Mike,

>IMHO, a user should not have to realize that all character postions are filled, so they have to press an additional key to change a character in a field.

If that is your opinion, define your framework to trap the right arrow key and never allow the user to leave the field this way. There was a running thread last week about preventing the user from using the backspace key, you'll be doing pretty much the same thing (different KeyCOde however ;-).