So I assume the problem is that on each TextBox you are listening for the
Enter event and then setting focus to another textbox that also listens for
the enter event.  That isn't quite making sense to me, however, if this is
the case I would set a bool value to signify that the focus is being set
from inside your code and not the keyboard.  Then in each enter event check
the bool to determine if you should continue setting focus to another
control.

As I am writing this, I think that I am not understanding the problem
correctly.  Please post more information.  Maybe and example of why you are
doing this so I can better understand.  Sorry, its been a long day and I'm
very tired.