This problem isn't specific to Word. It seems to happen with text boxes in browsers sometimes too.

On my old computer or in the text entry box in this forum, whenever I press up with the cursor on the top line, the cursor moves to the beginning of the line. Likewise when I press down at the bottom line, the cursor moves to the end of the bottom line. However, this behavior isn't exactly the same as home and end because when you press home for example, the cursor position is set to column 0 but when you use the up key trick the column information is preserved so that when you press down again the cursor will return to the column it was at before.

But this won't work in Word anymore. I'm using Windows 8 and Microsoft Office Professional Plus 2010. When I press up on the top line or down on the bottom line, the cursor doesn't move and nothing happens. Is there any way to get the old behavior back?