anything with !important will override anything of the same CSS style and works all the way down to ie6!
here's a little snippet that is ordered from weakest to strongest!
color: #333 !important;
color: #444 !important;
as you can see id is stronger than class, but with !important, a class is stronger than an id! Nonetheless, an id with !important is GOD!
initially, ids override classes, but even a class can override an id with !important!
this allows for an expanded amount of control over your elements!