Don't have Silverlight installed. This has only been happening since the last flash player update. I have scoured my registry for any flash player entries deleted them and disabled the chrome plug-in. (The flash player chrome was using was 10.1.xxx not the latest one) I downloaded and installed 10.3.xxx manually. So far so good.
If i have anymore trouble i will try installing Silverlight and see if that makes a difference.
Hope this helps if anyone else is having flash problems.