How about when an author, again in bk 2, seemingly decides they no longer like the way they set up a certain aspect in book 1 and continues to repeat the "new" fact over and over again, either trying to convince you or themselves that that's really the way things happened in the first volume? Yeah, annoys me, too.
As an aspiring author, I've written my share of slips, but why doesn't someone catch these things? Beta readers, an agent, an editor, a copy editor?
Are these mistakes enough to keep you from reading an author, or do you forgive them as well?