You probably tried to set the default paragraph style in the Tools > Document Settings > Paragraph Styles panel by moving the style to the Style for Event Types column. This only designates which styles will be available by using the TAB key to change styles.
The correct way to set the default paragraph style for an event type is to go into Tools > Document Settings and select the Contents panel under Event Hierarchies. With the event you want to modify chosen in the Setup Event type section, simply change the combo box in the Default Appearance of Context to the style you want to be the default style.
Tag: StoryView, Outine 4D