I think this is mostly just a question of how to word the question...
Prior to emacs 23.1, when pressing down-arrow or up-arrow the cursor would move up a whole line at a time even when that line was wrapped.
As of emacs 23.1, when pressing up or down-arrow at the head of a wrapped line, the cursor moves to the position within the same "line" which happens to fall beneath it's previous position. So instead of moving to the beginning of the next line, the cursor actually moves to character 81 (depending on the width of your buffer) within the same line.
I would like, very much, to restore the older behavior of always moving a whole line at a time.
M-x customize-option line-move-visual.