thank You for Your responses! Based on Your posts I have manage it.

In fact the problem was that I tried to automate the country combo behavior by setting is as bound control with object relationships. As I have written before I'm very new to StrataFrame and I like it because a lot of things are automated. So I tried to get it as automated as possible to take advantage of StrataFrame.

Now I have unbound combo with countries and I handle events manually.

Thank You ones more :-)