AJAX requests cause duplicate, invalid CSS includes and multi-nested response data output

Not sure if this is a views bug or a core bug, but since I currently can't replicate it outside of views, I'm posting this in the views issue queue.

The problem is that when making multiple AJAX requests on a view page (paging, sorting, filtering), two things happen:

1. Duplicate CSS imports are added, invalidly wrapped in divs (see https://skitch.com/duellj/rj63c/duplicate-css)
2. View output gets deeply nested in blank divs (see https://skitch.com/duellj/rj64u/nested-divs). This could get insane if the user interacts with the ajax requests for some time

The offending code seems to be in core misc/ajax.js:

    // We don't know what response.data contains: it might be a string of text
    // without HTML, so don't rely on jQuery correctly iterpreting
    // $(response.data) as new HTML rather than a CSS selector. Also, if
    // response.data contains top-level text nodes, they get lost with either
    // $(response.data) or $('<div></div>').replaceWith(response.data).
    var new_content_wrapped = $('<div></div>').html(response.data);
    var new_content = new_content_wrapped.contents();

    // For legacy reasons, the effects processing code assumes that new_content
    // consists of a single top-level element. Also, it has not been
    // sufficiently tested whether attachBehaviors() can be successfully called
    // with a context object that includes top-level text nodes. However, to
    // give developers full control of the HTML appearing in the page, and to
    // enable AJAX content to be inserted in places where DIV elements are not
    // allowed (e.g., within TABLE, TR, and SPAN parents), we check if the new
    // content satisfies the requirement of a single top-level element, and
    // only use the container DIV created above when it doesn't. For more
    // information, please see http://drupal.org/node/736066.
    if (new_content.length != 1 || new_content.get(0).nodeType != 1) {
      new_content = new_content_wrapped;
    }

But I'm not sure if it's a core issue or if views is returning invalid response data.