If you find that events in your 4D V6 forms aren't working when you expect, check that you have the events you are looking for turned on, in the place you need them.
For instance, if you want to detect when your form is sent behind another window or brought to the front, you should check for the On Activate or On Deactivate form events in the form method. If this doesn't work, open the form in the form editor and choose Form Properties... from the Form menu. Click on the Events tab and ensure that the On Activate and On Deactivate events are checked.
Similarly, if you want to detect a click on an object in the form method, ensure that the form (not the object) has the On Clicked property checked.