DE2 Expansion Header

There are a couple of variations of the DE2, for example I have the DE2-70. It looks like you have the original: http://www.terasic.com.tw/cgi-bin/page/archive.pl?language=english&categoryno=53&no=30

Assuming that, both files look correct, so perhaps GPIO_0[10] etc isn't where you think they are?

As a general debugging technique, I recommend that you _also_ assign those keys to four LEDs. If you see the LEDs react to key presses as expected, then you know that

1) your design was loaded correct and

2) the problem isn't with the KEY input.

Tommy