Every book has mistakes in it.
The situation regarding the text of Ulysses is catastrophic. It has now become a serious obstacle to reading the book at all. There is a bitter irony in the fact that one of the masterworks of Modernism, a monumental text supposedly under complete authorial control, more permanent than bronze, should now lie dispersed, in fragments, outside anyone's control. Rather than engaging in lamentations or indulging in pointless anger, it is probably more profitable to examine how things came to this parlous pass and to see if there are any ways out of it. But in fact the relative lack of awareness of this issue in, say, the 1960s, was a state of false, if now intensely desirable, innocence.