I used DXL before this time and also I have met this error in the past,
1- Insert a new action button to view,
2- Write Lotus Script under this button's Click event - For Exp : Messagebox "Sample"
3- Then Replace Style from any database view.
4- Then re-open the view in the designer and look at the action button's events,
5- Click event coming double times, there are 2 click event under the action button.
Did you see this bug about DXL ? I am waiting your response,