Asynchronous viewer update

Question

When call the pop function of an Array, I got this error.
The type of variable m_array is Array, when I found the running result is not correct, I changed to the debug mode. And the problem occured at the secentence m_array.pop(). Before call this secentence, there are three elements in Array( the length of Array is 3 ), and the type of element is Point. So I realy don't what's the problem it is!?
The problem occurs at the line 36 in the attach file, the calling code is
   var h:MinHeap = new MinHeap(function cmp(l:Point,r:Point):Boolean{return false;});
   var pt:Point = new Point;
   h.insert(pt.clone());
   h.extractMin();
   pt.x = 1;
   h.insert(pt.clone());
   pt.x = 0;
   pt.y = 1;
   h.insert(pt.clone());
   pt.x = 1;
   h.insert(pt.clone());
   h.extractMin();
The bug appear every time if you run in debug mode, and set a break point at line 36 in attach file.

Answer 1

The error message is same with the title.
The code causing error is: m_array[0] = m_array.pop();
If the program is run directly, there isn't error message, but the result is not correct. If it's run in debug mode, and the error message will appear at line 36 in the attached file( i.e. the code m_array[0] = m_array.pop() ).
The attached file is the error message dialog.