Grant permission interface rolled over (unable to create a site)

Hi all,

I got some issue on SharePoint 2010 Standard. When I want to grant some permissions for the users, I got a problem with the interface where all types of permissions are not on line.  Please have a look:

Another thing is that I can't create a new site, cause I got: 'an unhandled exception occurred in the silverlight application sharepoint 2010' Of course I did a research with this issue and I have tested already 'Web Page Security Validation' and this didn't brought anything new. 

Temporary solution I found is to click F12 on the keyboard and change the browser mode from IE10 into IE9.

Then all issues are gone. But because this is a production environment I would need some other solution.

Thanks in Advance

Przemo