(Unverified) Regression: Plugin hang with 7u4 and IE8/9

SYNOPSIS
--------
(Unverified) Regression: Plugin hang with 7u4 and IE8/9

OPERATING SYSTEM
----------------
OS: Windows (Tested on Windows 7)
Browser: IE8 or IE9

FULL JDK VERSION
----------------
java version "1.7.0_04"
Java(TM) SE Runtime Environment (build 1.7.0_04-b22)
Java HotSpot(TM) Client VM (build 23.0-b21, mixed mode, sharing)

Not reproducible with 7u3.
Reproducble by Licensee using 7u4, 7u5, 7u6-ea.

PROBLEM DESCRIPTION from LICENSEE
---------------------------------
Under certain circumstances an applet fails to (re)load, and the VM hangs. The only way to recover the situation is to kill the java process and reload the page.

The issue is reproducible with one of the applets on java.com, but not all applets exhibit the problem. The issue is also highly reproducbile using one of Licensee's applet-based products.

REPRODUCTION INSTRUCTIONS from LICENSEE
---------------------------------------

(See Comments for reproducibility note).
1. Load the Java Test Applet (using IE 8 or 9) and the 1.7.0_04 Oracle
   JRE): http://www.java.com/en/download/testjava.jsp

2. Navigate to another page in the same browser window

3. Use the browser's "back" button to return to the Java Test Applet
   page

4. Repeat steps 2 & 3 until the problem is seen... usually it can be
   reproduced in 1 to 3 iterations.