Adam,
I can reproduce the problem in your link finally. It happens when I use Absolute Urls setting (Editor1.UseRelativeLinks = false and Editor1.RemoveServerNamesFromUrl = false) and the page has 2 or more querystring items.
The following are the steps to reproduce the problems:
1. Click the link which has 2 querystring items:
2. Click the radio button "Use Absolute Urls".
3. Switch to "HTML" view, and insert an anchor link: <a href="#top">top</a>
4. Switch to "Normal" view then switch back to "HTML" view, you will find the anchor link has been changed as following:
<a href="http://cutesoft.net/example/Relative-or-Absolute-URLs.aspx?param1=1&param2=2#top">top</a>
The anchor link works fine when the page doesn't have any querystring item or only has one. My page needs many querystring items, and I must use Absolute Urls setting. Any idea to solve the problem?