Hi Gus...
To understand, you have to consider the problem as a window tree...
When you open modal windows only, the window tree is simple:
- Mother>1rst Child>2nd Child...
when you open child 2, Clid1 is blocked AND Mother is blocked
If you do the same thing with openchild for Child 1 and OPEN for child 2, you get the same result in term of who is blocked when you open the modal child 2: child 1 AND mother
BUT, if you do Mother---OpenSister(Sister1)>Open(Child1), opening child1 as modal blocks ONLY Sister1... Mother remains active (and all windows open as child y mother too)...
This allows by example to open multiple times the MAIN window and have totally separate windows trees (think word opening multiple documents)
Best regards