As none of the above worked for me, I thought I would share what I finally did to get it working.
It wouldnt work in either of the browsers I tried, IE and FF.
Tried older versions of Silverlight with no joy, remove and regisry clean up still no change.
I then remembered I had made some changes to try to stop MSN from auto running videos.
Reset IE to default settings (The one that requires a windows reboot) and after reboot I installed the newest version of Silverlight (v 5.1.41105.0) and everything worked, including in FF as well which as a little weird but took it as a win.
Hopefully this will help others 