A customer recently upgraded from 1.6.0_10 -> 1.6.0_11 and started to see the following exception with their applet preloader code:

Exception in thread "Thread-10" java.lang.NoSuchMethodError:
com.sun.deploy.net.HttpDownload.download(ILjava/net/URL;Ljava/io/InputStream;Ljava/lang/String;Ljava/io/File;Lcom/sun/deploy/net/HttpDownloadListener;)V
        at
com.sun.deploy.cache.CustomCache.downloadResourceToCache(CustomCache.java:544)
        at
com.sun.deploy.net.CustomDownloadEngine.actionHttpDownload(CustomDownloadEngine.java:1462)
        at
com.sun.deploy.net.CustomDownloadEngine.actionDownload(CustomDownloadEngine.java:1002)
        at
com.sun.deploy.net.CustomDownloadEngine.getCacheEntry(CustomDownloadEngine.java:1608)
        at
com.sun.deploy.net.CustomDownloadEngine.getResourceCacheEntry(CustomDownloadEngine.java:1723)
        at
com.sun.deploy.net.CustomDownloadEngine.getResourceCacheEntry(CustomDownloadEngine.java:1650)
        at
com.sun.deploy.net.CustomDownloadEngine.getCachedResource(CustomDownloadEngine.java:658)
        at
com.sun.deploy.cache.CustomCacheApp.doDownload(CustomCacheApp.java:241)
        at
com.bank.casa.navshell.preloader.JPIPreLoaderApplet6$PreLoaderThread.doDownload(JPIPreLoaderApplet6.java:584)
        at
com.bank.casa.navshell.preloader.JPIPreLoaderApplet6$PreLoaderThread.run(JPIPreLoaderApplet6.java:414)

They have developed the following workaround
*1.6.0_10*
CustomDownloadEngine.getHttpDownloadImpl().download(
    conn.getContentLength(), conn.getURL(), is,
    conn.getContentEncoding(), ce.getTempDataFile(), null);

*1.6.0_11*
CustomDownloadEngine6U11.getHttpDownloadImpl().download(
    conn.getContentLength(), conn.getURL(), is,
        conn.getContentEncoding(), ce.getTempDataFile(), null,0);

By adding the dummy argument, they have resolved the exception in _11.