FULL PRODUCT VERSION :
java version "1.7.0"
Java(TM) SE Runtime Environment (build 1.7.0-b147)
Java HotSpot(TM) 64-Bit Server VM (build 21.0-b17, mixed mode)

ADDITIONAL OS VERSION INFORMATION :
Microsoft Windows [Version 6.1.7601]

A DESCRIPTION OF THE PROBLEM :
When "v" is pressed in the Java Console (when running a Java Web Start application), instead of displaying the thread stack - "null" is displayed.

v
Dump thread stack ...
----------------------------------------------------
null
----------------------------------------------------
Done.

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Launch a JNLP app (e.g. from the Java Tutorial - http://download.oracle.com/javase/tutorial/uiswing/components/button.html)

I used the following:
http://download.oracle.com/javase/tutorialJWS/uiswing/components/ex6/ButtonDemo.jnlp

With the Java Console displayed press "v"
(other options seem to work fine)

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
Expect the thread stack to be output
ACTUAL -
Dump thread stack ...
----------------------------------------------------
null
----------------------------------------------------
Done.

REPRODUCIBILITY :
This bug can be reproduced always.