There's a number of small publishers who are, shall we say, getting up there in years. Some are just overall tired and I think a couple are approaching senility. The applies even more so to some of the authors.

I don't think the errors you speak of would qualify as classic cases of incompetence. I think the parties involved (author and publisher) do the best they can, the best they are capable of, and unfortunately the results speak for themselves. So this isn't laziness or sloppy writing, rather a failing memory in many cases.