I indeed dont understand this lost memory when the box you open is a modal dialog.thats want to say you must click a button to free this dialog mandatory (must select a file or cancel).
if you make a loop with 100 times you must click to make a choice 100 times!
where is the problem ?

*for whose interesting this some links on my blog on common dialogs (this above included)
http://yousfi.over-blog.com/2016/01/working-with-common-dialogs-part1.html
http://yousfi.over-blog.com/2016/01/working-with-common-dialogs-part2.html