My b2evolution Version: Not Entered

v 1.9.3
Found a bug? in the Admin HTML checking of a post, where it parses the URL.
If a link is formatted eg:
<a href="http://www.thissite.com/owner/pageto.goto.htm">Page to go to</a> then it works as expected.
BUT, this doesn't:

<a href="http://www.geocities.com/nelstomlinson/research.bibliography.html">www.geocities.com/nelstomlinson</a>
=
Found invalid URL: URL not allowed

Huh?
To get around the error thrown about an Invalid URL, I have removed the <a> tagging.
Does someone in the devs not like geocities or something ;-)