problems with set loc of a stack

[Tiemo Hollmann TB]

Hello,

I have a substack which is frequently shown and hidden. The first time I do:

-Open stack "foo"

-Show stack "foo"

-Set the loc of stack "foo" to the loc of the defaultstack

When closing the window, I just hide stack "foo"

>From the second "opening" I just:

-Show stack "foo"

-Set the loc of stack "foo" to the loc of the defaultstack

Where I am struggeling is, that the set of the loc, doesn't works for the
first time (the stack is shown somewhere at 0,xy), from the second show on,
the set loc works as wanted. Why does the set loc doesn't works for the
first opening of the window?

Any idea? Thanks for any comment

Tiemo