I decided to give linking my Facebook account to my OpenID delegate page another go last night.
Lo and behold, it still didn’t work. But this time, I got a useful error message!

After some Googling and reading, I finally figured out that I needed to add the following two lines to the source of my delegate page. Now I have a delegate page that works with OpenID 1.1 and OpenID 2.0.
Once I got that, I was able to link Facebook to my MyOpenID account. The weird logging in and out issues I reported a couple of weeks ago also seem to be resolved.
<html>
<head>
<!-- OpenID 2.0 delegate information -->
<link rel="openid2.provider" href="http://www.myopenid.com/server" />
<link rel="openid2.local_id" href="http://yourusername.myopenid.com/" />
<!-- OpenID 1.1 delegate information -->
<link rel="openid.server" href="http://www.myopenid.com/server" />
<link rel="openid.delegate" href="http://yourusername.myopenid.com/" />
</head>
<body>
</body>
</html>


[...] Just managed to get Facebook to recognise my OpenID with the help of this post. [...]
Posted by Facebook OpenID at tom.morr.is on June 6th, 2009.