nonexistant padding error?

The CSS Validator complained about padding missing a unit... in a block where I had not added padding at all. In fact, I had not added padding in the style sheet I validated at all.

44	Value Error : padding  only 0 can be a length. You must put an unit after your number : 2


lines 42-46:
a {
    text-decoration: none ;
    height: 100% ;
    background-image: none !important ;
}