I have this [site](http://www.canalonesbastimar.com). As you can see using IE7 the width of the `header` is widther than the content below, I mean It does not have `width: 960px` as I expected. Could you tell me why?

This is the code of the `header` tag:

```
header {
  border-top: 6px solid #9F9F9F;
  margin: 0 auto;
  background-color: $amarillo;
  width: 960px;
  padding: 19px 34px;
}

```