Javaws can not load the proxy configuration from Firefox browser

I open this CR for 6396680, pls re-evaluate.

Snv 34, vermillion 06, jdk1.5.0_06 b04.

Firefox is the default browser on Vermillion.

reproduce steps:
1. Start firefox
2. Load http://java.sun.com/products/javawebstart/apps/draw.jnlp

see the following exceptions:
com.sun.deploy.net.FailedDownloadException: Unable to load resource: http://java.sun.com/products/javawebstart/apps/draw.jar
at com.sun.deploy.net.DownloadEngine.actionDownload(DownloadEngine.java:926)
at com.sun.deploy.net.DownloadEngine.getCacheEntry(DownloadEngine.java:1024)
at com.sun.deploy.net.DownloadEngine.getResourceCacheEntry(DownloadEngine.java:1099)
at com.sun.deploy.net.DownloadEngine.getResourceCacheEntry(DownloadEngine.java:1033)
at com.sun.deploy.net.DownloadEngine.getResource(DownloadEngine.java:141)
at com.sun.javaws.LaunchDownload.downloadJarFiles(LaunchDownload.java:833)
at com.sun.javaws.LaunchDownload.downloadEagerorAll(LaunchDownload.java:749)
at com.sun.javaws.Launcher.downloadResources(Launcher.java:1068)
at com.sun.javaws.Launcher.prepareLaunchFile(Launcher.java:455)
at com.sun.javaws.Launcher.prepareToLaunch(Launcher.java:164)
at com.sun.javaws.Launcher.launch(Launcher.java:94)
at com.sun.javaws.Main.launchApp(Main.java:299)
at com.sun.javaws.Main.continueInSecureThread(Main.java:209)
at com.sun.javaws.Main$1.run(Main.java:106)
at java.lang.Thread.run(Thread.java:626)

The same issue on Mustang.

Change the setting on ControlPanel, General -> Network Settings -> Use proxy server
Address webcache.prc.sun.com Port 8080, the draw app is launched correctly.

Not reproducible with root user.