well it's just what I said isn't it?
Yes, of course. Additionally the second link has link to forum threads with example code too.
Just in case: I've found this while struggling somewhat similar problem with analog sensor on a breadboard: http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1291144300
But mine works ok if connected without anything directly to Arduino. Have you tried to eliminate breadboard?