Mainly for Google, but you might experience this.
I was going to post a comment to Modern Perl Books, but didn't. Seems that when I try to use my LiveJournal OpenID, I get an "unclosed token" error.
As it turns out, it's an MT error. If you have "too many" friends, LJs FOAF (Friend Of A Friend) response is too large for MT to handle. The workaround is to create a "FOAF-knows" friends group and only add yourself to it.