Some time ago several clients told me that on some machines with Vista Image Uploader for Java was unable to initialize.
Nothing was shown at all inside applet body. I tried to reproduce this bug but failed. Some of our clients (his name is Arthur) agreed to help me in fixing this problem. I have sent him about a dozen of log versions to find the real reason of the problem. The issue was in Vista operating system recognition. It turned out that not all JRE versions on Vista had "Vista" word in their os.name system property. On some JRE versions it contained "WindowsNT Unknown" value. Thus I have fixed this by adding one more case to OS type recognition algorithm. Now it looks to work fine. Thanks to Arthur one more time.