A trick from the French guy Pabra
Not a total resolve but...
About the dialog Box
It's a problem of refreshing - filling of the dialog box!
Moi has not the time to explore directories and stock them in memory!

So (in any view of Moi ) open one time the file menu Export
the Dialog box apears disapears
then it's the trick (in any view of Moi )
move the mouse over the selected object
right click on it and the Dialog box apears disapears, after 3 - 4 times of this view "right click method"
it's becoming stable because directories are now checked and input the memory!
Not very practicle but that works and you can now import, export etc..

There is maybe a file system who manage tempo of the dialog boxes on MAC?