The pins need to be defined as digital inputs or digital outputs. I believe that by default pins 9-18 are defined as outputs, and you need to change that in the code.
I don't know what you're programming with, but for WPILib, you can use:
Code:
#define IN 1
#define OUT 0
void Initialize (void)
{
DefineControllerIO(IN,IN,IN,IN,IN,IN,IN,IN,IN,IN,IN,IN,IN,IN,IN,IN,IN,OUT);
}//end Initialize