1) Import an application which requires previous version of JRE to system cache
2) Make sure that the required jre is not available for JavaWebStart
3) Launch the application, it will download and install required JRE
4) When it tries to launch application, an error dialog is shown

Given below is the error information..
Close the error dialogs, now relaunch the application, it works fine.

JNLPException[category: Launch File Error : Exception: null : LaunchDesc:
<jnlp spec="1.0+" codebase="http://jal.sun.com/webapps/jawsautodl/AutoDL/j2se/">
  <information>
    <title>J2RE 1.4.2_07 Installer</title>
    <vendor>Sun Microsystems, Inc.</vendor>
    <homepage href="null"/>
  </information>
  <security>
    <all-permissions/>
  </security>
  <resources>
    <j2se href="http://java.sun.com/products/autodl/j2se" version="1.3+"/>
    <jar href="http://jal.sun.com/webapps/jawsautodl/AutoDL/j2se/javaws-1_0_1-j2re-1_4_2_07-inst-solaris-sparc.jar" download="lazy" main="false"/>
    <jar href="http://jal.sun.com/webapps/jawsautodl/AutoDL/j2se/javaws-1_0_1-j2re-1_4_2_07-data-solaris-sparc.jar" download="lazy" main="false"/>
    <property name="javaVersion" value="1.4.2_07"/>
    <property name="platformVersion" value="1.4"/>
    <property name="installerLocation" value="javaws-1_0_1-j2re-1_4_2_07-data-solaris-sparc.jar"/>
    <property name="installerEntry" value="jre.dat"/>
    <property name="licenseEntry" value="LICENSE"/>
    <property name="execString" value="/bin/sh {1} {0} {2}"/>
    <property name="waitString.0" value="[yes or no]"/>
    <property name="responseString.0" value="yes"/>
    <property name="javaPath" value="j2re1.4.2_07/bin/java"/>
    <property name="isSolarisInstall" value="yes"/>
    <property name="verbose" value="true"/>
  </resources>
  <installer-desc main-class="com.sun.webstart.installers.Main"/>
</jnlp> ]
at com.sun.javaws.Launcher.executeInstallers(Launcher.java:633)
at com.sun.javaws.Launcher.handleApplicationDesc(Launcher.java:386)
at com.sun.javaws.Launcher.handleLaunchFile(Launcher.java:218)
at com.sun.javaws.Launcher.run(Launcher.java:165)
at java.lang.Thread.run(Thread.java:595)