itext XMLWorkerHelper ignores value attribute of <li> tags

Question

I'm using itext 5.5.6 with XMLWorker 5.5.6 to generate pdf from html that cames from ckEditor. Users can also paste some text from word documents and this results sometimes in something like this:

<ol>
   <li>some text1</li>
   <li>some text2</li>
   <li>some text3</li>
</ol>

this results in ckEditor and in html as

1. some text1
2. some text2
3. some text3

But if itext convert this html to pdf, it ignores the value of li-tags and sets it to "1." and this results in something like

1. 2. 3.

Does somebody knows a way, make itext read and also use the numeric value of a li-tag?

Thanks in advance.