Hi M.Tahmasebi,
Thanks for reporting this problem.
As I see it, these are two problems actually. First, I agree that the close box shouldn't be that close to the window's border in RTL culture, and I opened a new tracker entry on that one here.
Your primary problem seems to be the other problem, that the clickable area for the close box is not correct. I opened another tracker entry on that problem. Please view it here and follow up on our progress.
Hope this covers your problems and again, thanks for your report.
Palli