Olaf,

Thanks for your thoughtful reply to my question.

You are right, and that is usually the strategy that I try to use. However, in this case I failed to create the subclass for this particular case, and although I could create the new subclass, the problem was then substituting it for the class that I originally used in the original container class. (All this class in class in class terminology gets confusing. But, I think you can see what I was trying to do.)

The problem doesn't come up often, but I was wondering how other people dealt with it.

Again, thanks for taking the time to reply to my question.

Jim