Just wanted to say that I have managed to install ZA Extreme 10.0.241 successfully; and that is including the securtiy toolbar (it works!)
With the toolbar; I have virtualization on, I have cleared the virtual data, opened up FireFox 4.0.1 and the toolbar was still there! I have literally messed about with the web security and browser virtualization settings for the past 15 mins (with shut downs between) and the toolbar is still there. I am very pleased.
I first installed Extreme (using the full file set-up, 247 MB size) with the computer disconnected and afterwards the toolbar works. I then uninstalled Extreme and installed it with the computer connected to the interent, the toolbar still works despite me messing about with the settings and clearing the virtual data constantly.
It's all good (for the moment!)