Please make sure UAC is Enabled and User is Admin user on windows 7.
How to reproduce?

1.) Make sure no Cache exist, run javaws -uninstall to be on the safer side
2.) Uninstall all JRE and JDK from the machine.
3.) Install 6u14 JDK bundle with Public JRE.
4.) Check JCP cache viewer nothing exist.

With JDK bundle the issue is reproducible on Vista as well.
Now I tried the following command on Both window 7 and Vista OS.
"C:\Program Files\Java\jre6\bin\javaws.exe" file exist on the machine but when i tried "C:\Program Files\Java\jre6\bin\javaws.exe -silent -import -reverse -javafxau -J-Dkernel.download.dialog=false "http://dl.javafx.com/javafx-cache.jnlp"

This works fine on Vista but on Windows 7 it is not showing any jar entry inside JCP cache viewer.
4.) I tried running foloowing command.
"C:\Program Files\Java\jre6\bin\javaws.exe" -import -reverse -javafxau -J-Dkernel.download.dialog=false "http://dl.javafx.com/javafx-cache.jnlp"
5) Got error. Here is the details.
CouldNotLoadArgumentException[ Could not load file/URL specified: http://dl.javafx.com/javafx-cache.jnlp]
at com.sun.javaws.Main.launchApp(Unknown Source)
at com.sun.javaws.Main.continueInSecureThread(Unknown Source)
at com.sun.javaws.Main$1.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)

com.sun.deploy.net.FailedDownloadException: Unable to load resource: http://dl.javafx.com/javafx-cache.jnlp
at com.sun.deploy.net.DownloadEngine.actionDownload(Unknown Source)
at com.sun.deploy.net.DownloadEngine.getCacheEntry(Unknown Source)
at com.sun.deploy.net.DownloadEngine.getCacheEntry(Unknown Source)
at com.sun.deploy.net.DownloadEngine.getResourceCacheEntry(Unknown Source)
at com.sun.deploy.net.DownloadEngine.getCachedFile(Unknown Source)
at com.sun.javaws.jnl.LaunchDescFactory.buildDescriptor(Unknown Source)
at com.sun.javaws.jnl.LaunchDescFactory.buildDescriptor(Unknown Source)
at com.sun.javaws.Main.launchApp(Unknown Source)
at com.sun.javaws.Main.continueInSecureThread(Unknown Source)
at com.sun.javaws.Main$1.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)