Norton Toolbar stopped working in IE

I am currently using IE9, Firefox 5.0.1, Vista Business &  NIS 2011 18.6.0.29

My toolbar went missing on IE9 after the 13/7/11, it is shown as enabled in 'Manage Add ons' but is not listed in the available toolbars.

I have tried uninstalling & reinstalling IE9 (the same problem occurs in IE8).

Firefox toolbar is working fine.

Any suggestions would be greatly appreciated.