>If the parent class method is supposed to disable/enable any other
>objects on the form, then make sure it uses a relative reference
>to those objects. In this case ensure that hierarchy of the class
>structure that is assumed in the parent class remains the same in
>your derived class. Also see if you added any code in Click method
>of your derived txtButtons class. If you did, then insert DODEFAULT()
>statement at the beginning of the method to let the parent class
>method execute itself, otherwise you are simply overwriting the
>functionality of the parent class.

DODEFAULT(). That's something new for me... And a good one!