Why do group ID's change when cloning a stack

[Claudi Cornaz]

I did some further testing and it turns out like this:

All objects (at least the ones I tested and I did most) don't change id
when the stack is cloned. That is all controls that are not part of a 
grp!

The id of all outermost grps don't change but the id's of ALL controls 
in a grp
will change, including the id's of nested grp's. So each and every 
control in a grp
get's it's id changed when the stack is cloned, except the id's of the 
outermost
grp's.

What would be the reason behind this? Why doesn't the id of the 
outermost
grp's change but each and every control in each grp get's a new ID.

What will happen when I clone a stack with hundred of grp's.
How much time wil this take if each control in all these grp's need to 
be reIDed.

I can live with the fact, well I will have to, there obviously is no 
choice, but I sure like to know!

Best wishes,
Claudi