htmlDocument.GetElementById returns element with same name, not id

First time using HtmlAgilityPack, i'm retrieving nodes inside an html that has 2 different elements, sharing a value as id for one and as name for the other:

    <span name="abc"></span>
     . . .
    <div id="abc"></div>

When i use GetElementById("abc") i end up getting the element whose name, and not the id, is the one specified. Hows so?

Thanks in advance