If you can switch to 4.x, do it. No, 3.x.x doesn't support IE9. Read through the forums and you'll see many references to that fact. Also, you have to force the meta tag for X-UA-Compatible to return as the first response header, and that's only possible with a filter or phase listener. A simple HTML meta tag won't do it.
But how do you do to put the X-UA-Compatible in first position of the <head>? I'm trying with servlet filter but richfaces head are always in first.
Thanks for advice