FULL PRODUCT VERSION :
java version "1.6.0-rc"
Java(TM) SE Runtime Environment (build 1.6.0-rc-b104)
Java HotSpot(TM) Client VM (build 1.6.0-rc-b104, mixed mode, sharing)

ADDITIONAL OS VERSION INFORMATION :
Microsoft Windows XP [Version 5.1.2600]

EXTRA RELEVANT SYSTEM CONFIGURATION :
tomcat web server version 5.5.7

A DESCRIPTION OF THE PROBLEM :
when referencing a jar resource in the jnlp file via the href reference the href reference must end in .jar for web start to download the jar.

working example:
<jar href="/ICE/Jar/commons-httpclient-3.0.jar"/>

downloads fine in jre 1.5.x and jre 1.6.x

bug example: <jar href="/ICE/Jar/commons-httpclient-3.0.jar;jsessionid=BD307F0DDCF0F9E36B9D4C16F30DF601"/>

downloads fine in jre 1.5.x broken in jre 1.6.x

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
create a jar resource that can be downloaded from a web server with a url that does not end in .jar.
Reference this url in a jnlp file.

example: <jar href="/ICE/Jar/commons-httpclient-3.0.jar;jsessionid=BD307F0DDCF0F9E36B9D4C16F30DF601"/>

downloads fine in jre 1.5.x broken in jre 1.6.x

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
The jar file is downloaded from the url and used by the application launched via the jnlp file
ACTUAL -
The application referenced in the jnlp file does not start

ERROR MESSAGES/STACK TRACES THAT OCCUR :
No information is displayed in the java console

REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
<?xml version="1.0" encoding="UTF-8"?>
<jnlp codebase="http://localhost:8080/ICE">
<information>
<title>Segment Control</title>
<vendor>ICE</vendor>
<homepage href="http://localhost:8080/ICE/index.html"/>
<description kind="short"></description>
</information>
<security><all-permissions/></security>
<resources>
<j2se version="1.5+" initial-heap-size="64M" max-heap-size="128M" href="http://java.sun.com/products/autodl/j2se"/>
<jar main="true" href="/ICE/Jar/AppSegmentControl.jar;jsessionid=BD307F0DDCF0F9E36B9D4C16F30DF601"/>
<jar href="/ICE/Jar/jdom.jar;jsessionid=BD307F0DDCF0F9E36B9D4C16F30DF601"/>
<jar href="/ICE/Jar/commons-codec-1.3.jar;jsessionid=BD307F0DDCF0F9E36B9D4C16F30DF601"/>
<jar href="/ICE/Jar/commons-httpclient-3.0.jar;jsessionid=BD307F0DDCF0F9E36B9D4C16F30DF601"/>
<jar href="/ICE/Jar/commons-logging.jar;jsessionid=BD307F0DDCF0F9E36B9D4C16F30DF601"/>
<jar href="/ICE/Jar/junit-4.0.jar;jsessionid=BD307F0DDCF0F9E36B9D4C16F30DF601"/>
<jar href="/ICE/Jar/forms-1.0.7.jar;jsessionid=BD307F0DDCF0F9E36B9D4C16F30DF601"/>
<jar href="/ICE/Jar/junit-4.0.jar;jsessionid=BD307F0DDCF0F9E36B9D4C16F30DF601"/>
<jar href="/ICE/Jar/jfreechart-1.0.1.jar;jsessionid=BD307F0DDCF0F9E36B9D4C16F30DF601"/>
<jar href="/ICE/Jar/jcommon-1.0.0.jar;jsessionid=BD307F0DDCF0F9E36B9D4C16F30DF601"/>
<jar href="/ICE/Jar/synthetica.jar;jsessionid=BD307F0DDCF0F9E36B9D4C16F30DF601"/>
<jar href="/ICE/Jar/spring.jar;jsessionid=BD307F0DDCF0F9E36B9D4C16F30DF601"/>
<jar href="/ICE/Jar/log4j-1.2.12.jar;jsessionid=BD307F0DDCF0F9E36B9D4C16F30DF601"/>
<jar href="/ICE/Jar/ICEProjectLib.jar;jsessionid=BD307F0DDCF0F9E36B9D4C16F30DF601"/>
<jar href="/ICE/Jar/looks-2.0.2.jar;jsessionid=BD307F0DDCF0F9E36B9D4C16F30DF601"/>
</resources>
<application-desc main-class="com.ice.desktop.controller.AppSegCtrlLaunch">
<argument>BD307F0DDCF0F9E36B9D4C16F30DF601</argument>
<argument>150</argument>
</application-desc>
</jnlp>


---------- END SOURCE ----------

Release Regression From : 5.0u9
The above release value was the last known release where this
bug was not reproducible. Since then there has been a regression.