So the problem is here:

When I create an instance of this 'X1' zclass an I enter to this propertysheet/section ,   I can change the default value of 'section1' which was 'left side' to 'center side' for example.

But then if i change the original default value of my zclass 'X1' to 'right side' let say. The change will not be reflected in my instance,   which is okey because i have change d the value to 'center side' before.

Another case is when I create another instance of 'X1' zclass   without making any change to the value of 'section1' and click on save changes, then if I change the default value in the zclass, the change will not be reflected in this instance.

So the question is:

There is a way to recognize when an instance will not take the changes that are make to the default values of a propertysheets (in this case thepropertysheet 'section' ) of a zclass from which they inheritance?

I try with this lines in an external method, but nothing:

   self=self._getOb('instanceTest')         # instanceTest is the name of the instance of the 'X1 Zclass'
   a=getattr(self,'meta_type')
   b=getattr(self.__class__,'meta_type')
   # in this example the answer was the same: X1

   a=eval('self.__class__.propertysheets.section._propertyMap()')
   b=eval('self.propertysheets.section._propertyMap()')
   # the answer was again the same: {'id': 'section1', 'type': 'string','meta': {}, 'mode': 'w'}

   #I try acceding to the zclass to know if it was different from theinstance...
   a=eval('self.Control_Panel.Products.X.propertysheets.common.section.propertyMap()')
   # the answer not help: {'id': 'section1', 'type': 'string', 'meta': {}},