I was just trying to log into the ATO Business portal, and found that I can't now, looks like the issue cropped up as of Snow Leopard and is due to some Java changes.

Here is the fix:

• Option click on the CSI Installer and select: Show Package Contents
• Then navigate to: Contents > Resources > jarfiles
• Copy csi.jar to:
  /System/Library/Frameworks/Java.VM.Framework/Versions/1.6.0/Home/lib/ext

Now you need to set the Java applet priority to 32bit:

• Navigate to Applications/Utilities and open: Java Preferences.app
• Change the priority of both sections on the General tab so that 32-bit is first

Now you will be able to log into the ATO Business Portal again! With Safari at least, recent versions of FF don't let you enter your password when CSI pops up for some reason.

This probably fixes issues with other Java apps as well.