.. is different than in IE8?

I use IE9 at home and IE8 at my primary office.

Yesterday at the office I turned on audio notifications from Setup/Update My Account.

Today at home I remembered the reason I had turned off audio notifications- every time the site tries to play a sound it gives me an error message telling me it can't find ".wav".

So, I go to turn off audio notifications. Nope - not in native mode IE9. The Update My account page is different and the option to turn on/off audio notification is not there.

I had to go to compatibility mode - then I get the Update My Account page that has the option.

Odd.