<= IE8 memory leak, IE9 - fine?

Question

JavaScript

Hello,
The problem is this:
We have a complex AJAX based application.
It has a wizard that opens in a browser popup, it has a lot of complex controls and all sorts of JS. When you open the popup, it eats somewhere around 60 meters, this is normal, it's not scary.
The problem is that when this popup is closed, IE8 and IE7 let go about 7 meters, and the rest goes into the leak, and so it can eat up to 3 or more GB. The interesting thing is that IE9 handles this remarkably well, there are no licks. There are no faces in FF either.
The first thing that came to my mind was that there are circular references, and IE does not let go due to the fact that the DOM and JS are in different COM libs, but I came across an article where Microsoft says that they fixed it in IE8.
Actually, the question is, is it possible that Microsoft is cunning, and they didn’t fix it somewhere, and that the real fix came only with IE9, or maybe then since there are no more cyclic licks in IE8, then there are ideas that it could still be (what pulls in IE8 but doesn't pull in IE9)?
Thank you!

Answer 1

webo.in/articles/habrahabr/24-memory-leaks-detection-tools/

Answer 2

Did you write Ajax yourself or from a framework?

Answer 3

Do you specifically clean up all the memory you no longer need and tear all the created links, or do you rely on the garbage collector?