By running this test with IE, FF, Safari and Opera, you can easily see the culprit with IE.

This test case has two buttons "DivLevelUpdate" and "FormLevelUpdate". The DivLevelUpdate button adds a div to the page which has an external CSS link. Clicking on "DivLevelUpdate" button should render a new blue div. It does happen with all browsers but IE.

1
- This button should be clicked first, The following button will add a div element with link element (external css), the new div should be blue.

- The following button will add a form element with a link element and the new div should be blue.