IE 9 Compatibility issues

IE 9 is a new browser and there are a few display issues with the forum like wrong size when opening DHTML window as well as some WYSIWYG editor problems.
 
For now, we need a workaround to prevent the issues from happening for IE9 users by asking IE 9 to emulate IE 8's display engine:

If you are on IIS 7 (Windows 2008 Server):

Add the following section to your web.config file, between <system.webServer></system.webServer>

        <httpProtocol>      
             <customHeaders>      
                 <clear />      
                 <add name="X-UA-Compatible" value="IE=EmulateIE8" />      
             </customHeaders>      
         </httpProtocol>

If you are on IIS 6 (Windows 2003 Server):

You can add the following meta tag:

<meta http-equiv="X-UA-Compatible" content="IE=EmulateIE8" /> 

to the Head tag of the outermost master pages, and they are:

• For the Classic Theme
  • ~/MasterPage.master
  • ~/App_Templates/Classic/popup.master
• For the Original Theme
  • ~/App_Templates/Original/Regular.master
  • ~/App_Templates/Original/popup.master

Alternatively (actually easier), if you have access to the IIS Manager, you can add a custom HTTP header for the forum folder:

Custom header name: X-UA-Compatible
Custom header value: IE=EmulateIE8

See the screen shots on this thread.