When cleaning a dl tag that contains forbidden children like p or br, they are wrapped in a div now since version 2.28. This is wrong, when a div is a child of a dl, it only allows "one or more dt elements followed by one or more dd elements, optionally intermixed with script-supporting elements.". Removing div as preferred child again doesn't fully fix this, for example the following example shows that plain text is still kept as child which also isn't allowed:
<dl><p>Paragraph1</p><dt>Term</dt><br /><dd>Definition</dd><p>Paragraph2</p></dl>
is cleaned as
<p><br /></p><p></p><dl>Paragraph1<dt>Term</dt><dd>Definition</dd>Paragraph2</dl>
I forgot to mention, this is with HTML 5 tag definitions, with HTML 4 the example input is kept as-is.