This took me 6 hours with Commsec on the phone to work out but I'll bet its one of two problems.
Firstly make sure Java is up to date and installed. Assuming you've done that and it still doesn't work you'll have to do enable Java extensions in Safari preferences . Google will show you how.
GL
Finally @Change Mac's Rule!!! How many times have you spent hours waiting on MS updates when you absolutely need access to your lap top Hmmm ;-)
