Following on from my previous post relating to setting problems with the setting of the master page content type to a value other then IE=8, I found some more useful information. The post I read actually referred to a problem with Silverlight following someone changing the content type to IE=Edge, so I wondered if the same solution was true. To read the original blog click here.
First of all, check that this is indeed the problem in your environment by firing up IE 10, press F12 to bring up the developer tools, and force the User Agent string to IE 8.
All we need to do now is apply the hotfix to ASP.NET which updates the browser definition files (see KB2600100).