AutoSpell Checking

Hi All, I just bought the new 11" Macbook Air. It seems that when ever I am in a text box online (google search bar, facebook chat or even this box I am typing into) it does not give the red dotted line under the mispelled word! I have checked to ensure that auto spelling is enabled using system preferences and also my firefox preferences. Any help is greatly appreciated

Cheers

This sounds like a software issue rather than a hardware one.