regreesion test javax/swing/ToolTipManager/4768127/bug4768127.java fails in b90

Java Version: build 1.6.0-rc-b90
PlatWrom: SNBOHMKHJYFMYXO

Problems:
The regression test fails in b90 promotion build.

Errors as following:

---------System.err:(5/406)----------
java.lang.Error: Extra MouseMotionListeners were added to the label "Label 1" by ToolTipManager
at bug4768127.destroy(bug4768127.java:86)
at com.sun.javatest.regtest.AppletWrapper$AppletThread.run(AppletWrapper.java:157)
at java.lang.Thread.run(Thread.java:619)
STATUS:Failed.Applet thread threw exception: java.lang.Error: Extra MouseMotionListeners were added to the label "Label 1" by ToolTipManager
result: Failed. Execution failed: Applet thread threw exception: java.lang.Error: Extra MouseMotionListeners were added to the label "Label 1" by ToolTipManager


test result: Failed. Execution failed: Applet thread threw exception: java.lang.Error: Extra MouseMotionListeners were added to the label "Label 1" by ToolTipManager

How to reproduce:
1. set up JAVA_HOME to mustang b90
2. run the attached script.

Please see jtr file as attched.