This is the error I get after logging into Stack with my LightOpenID provider script.
The OpenID Provider issued an assertion for an Identifier whose discovery information did not match.
Assertion endpoint info: ClaimedIdentifier: http ://sub.mydomain.net/?cgillis ProviderLocalIdentifier: http ://sub.mydomain.net/?cgillis ProviderEndpoint: http ://sub.mydomain.net/ OpenID version: 2.0 Service Type URIs: Discovered endpoint info: [{ ClaimedIdentifier: http ://specs.openid.net/auth/2.0/identifier_select ProviderLocalIdentifier: http ://specs.openid.net/auth/2.0/identifier_select ProviderEndpoint: http ://sub.mydomain.net/ OpenID version: 2.0 Service Type URIs: http ://specs.openid.net/auth/2.0/server },]
Provider script: https://gist.github.com/1072612
I should note the provider has select_id set to true. Everything works if it's set to false.