Odd Problem With window.close()

I have an odd problem with window.close() or self.close() (Both create the same issue). I have a window that pops up when a link is clicked, a simple form is submitted then a button is shown that when clicked closes the window using the aforementioned method. This works fine, the problem I'm having is when this is performed multiple times. After 10 - 20 times of performing this task the pop up window no longer loads (It's not hitting any code within the pop up, not even the Page_PreInit). The problem doesn't occur in Firefox or Safari, only IE. It's definatly linked to window.close() as if the window is closed using the X in the top right corner everything works fine. Any ideas what might be causing this? Is it an IE bug?

From stackoverflow

• Did you check the memory footprint of Internet Explorer while you were doing your tests? Because your problem might be a memory leak problem: http://msdn.microsoft.com/en-us/library/bb250448%28VS.85%29.aspx .

  If this is the case, this page can help you: http://www.outofhanwell.com/ieleak/index.php?title=Fixing_Leaks