Ok, could you log a SAP note? it will add to our user case also.
We still haven't explained it 100% what has happened to us but we have a kind of workaround / best practice which is making sure we have captured screens shots of development and back ups of all scripts/imaging. Lastly, we do not update silverlight/internet policies unless it is very tightly controlled.
Is this Persona environment on an IDES box or dev, qas, production environment?
What version of personas are you running?