I finally figured out on Uncharted 2, that when I select the "Chapters" option and the 1st chapter appears, the L stick will not advance to additional chapters. However if you hit "X", then it will toggle thru all previously completed chapters, beginning on the chapter 1 screen, even if not having fully completed the game.
Thx for all the help offered,
I am facing the same problem. I am not able to access the chapters after completing Uncharted 2 twice ! this is so frustrating. It shows me Chapter 1 and does not allow me to scroll to other chapters like in Uncharted 1 .