You can’t use a LiveJournal OpenID account on LiveJournal — just go login with your actual LiveJournal account.
Now that is just… I don’t know,
stupid is far too mild a word to describe this idiocy in my opinion. This is bordering on Finnish state bureaucracy -stupid.
I too would like to go to LiveJournal and tell them which OpenID I want to have associated with my journal so that I can log in with it, but nooh… that would be just too simple and elegant, wouldn’t it?