STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
1. open the following url with java console open under IE(according to http://www.w3schools.com/TAGS/tag_basefont.asp, this tag is just supported by IE):
http://sqeweb/jsn/users/fred/deployment_ws/fred/deployment_6_UR_int_ws/deployment/src/plugin/FunctionalTest/FunctionalTest/html/HTMLBaseFontElementTest.html

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
No exception is thrown. and "@@@@test pass" should be printed in the console.
ACTUAL -
On IE:
The following exception is thrown:
java.lang.ClassCastException: sun.plugin.dom.html.HTMLElement cannot be cast to org.w3c.dom.html.HTMLBaseFontElement
at HTMLBaseFontElementTest.start(HTMLBaseFontElementTest.java:31)

REPRODUCIBILITY :
This bug can be reproduced always.

The applet source code is:
http://sqeweb/jsn/users/fred/deployment_ws/fred/deployment_6_UR_int_ws/deployment/src/plugin/FunctionalTest/FunctionalTest/src/HTMLBaseFontElementTest.java