Hi,
According to the source code of Wicket 1.3.3, Check#onComponentTag(ComponentTag) performs the following: CheckGroup group = (CheckGroup)findParent(CheckGroup.class); ... if (group.wantOnSelectionChangedNotifications()) { ... } The CheckGroup method is implemented as public class CheckGroup extends FormComponent implements IOnChangeListener { ... protected boolean wantOnSelectionChangedNotifications() { *return* false; } Check is not a subclass of CheckGroup. Thus, according to my understanding, it cannot call the protected method of CheckGroup. What is going wrong here? /Till