WordPress removes coding

Hi,

On this page (http://wonderfulwanderings.com/belgium/#belgium-unesco) I use ID’s to create jump links.
The jump links work fine, the problem is that WordPress strips half of them whenever I update the page.

For instance, if I want to jump from the index to the heading 3.1. UNESCO sites, my coding is this:

<span id=”belgium-unesco”></span>
 
<h3>3.1. UNESCO sites</h3>

I do it like this and not with <h3 id=”belgium-unesco”> because I want the jump to end before the heading so that you can still see the heading and I only achieve that by putting the id in a separate span tag and then adding the   to leave some room.

However, whenever I update the page, WordPress strips half of the <span id:”…”> and half of the &nbsp’s.

And this isn’t the first time I’ve had WordPress trip coding when updating pages.
I know it can happen when you change from html view to regular view (which shouldn’t, but it does), but in this case it even happens when I stay in the html editor.

Anybody know how to prevent this?

Thanks