Help: One Post has dodgy title link – permalink ish issue

Hi there,

My latest post has suddenly become broken (I have been editing it this evening)

If you look at the home page of:
http://www.davidjeanneret.co.uk/
you’ll see the post about me running, Hover over the title and you’ll see the link is to:
http://www.davidjeanneret.co.uk/%2
(in the html generated by the homepage it’s: href="http:/%2")
It should be pointing to:
http://www.davidjeanneret.co.uk/2010/03/03/david-better-love-running-by-may/
If you try and browse that it redirects back to:
http://www.davidjeanneret.co.uk/%2 (which isn’t there!)

If I ‘quick edit’ the post the slug field contains:
david-better-love-running-by-may

But if I Edit the post (whole edit page) the line where it normally shows the page URL and and Edit button to edit the slug shows:

Permalink: http:/%2 (Change Permalinks) (View Post) – the bracket bits are buttons.

Also on the home page – the comment link for that post is screwy too.

I really don’t get what’s gone wrong on this.

Any ideas?

Cheers

David