I ended up, by mistake, with some code on the RightClick event of a Checkbox. The code is supposed to start a popup menu. To recreate the problem just add some controls to an empty form, any, and then add a checkbox. On the RightClick event add the following code:

define popup edtshort shortcut relative from mrow(),mcol()
define bar _med_clear of edtshort prompt "Clear"
activate popup edtshort

Now start the form and click the right button on the check box. The menu pops up ok and you can only select "Clear". Select it and click the right button again: all the controls on the form disappear! Is this what they call Easter Egg?

Silvio