In the first code you are trying to mark the overridden instance method to static - so you get the compile time error.
This behavior is common when you implement an interface or extend a super class.
Have a look at the table in the Summary section of this tutorial -
http://download.oracle.com/javase/tutorial/java/IandI/override.html
As you see the error you get is 'static methods cannot hide the instance method in the super class / interface'.