Those are CHAPTER moves, and chapter marks are set automatically (the default setting is 10 min.). Using the CHAPTER buttons (|<< and >>|) will only work if there's a chapter mark 10 min. ahead or back, so going to next chapter might not do anything if no chapter mark to go to. Also, going 1 chapter back can take two presses since 1st press will go back to mark for chapter you're currently in, then 2nd press will move to previous chapter.
"SKIP/REPLAY" moves are with the large toggle button on the right.
Edited by wajo - 2/18/13 at 6:32pm