CCS5.1.1 printf() no ouptut in debug (using EK-LM3S1968 eval board)

I've just started using Code Composer Studio 5.1.1 (previously used a old version of Code Sourcery) and I can't get stdio to appear in the Console window (worked fine in CS). 

Note that Stellaris ek-lm3s1968 board examples appear to work fine but a simple  standard hello world...ie

#include <stdio.h>

/*
* hello.c
*/
void main(void) {
printf("Hello World!\n");

}

outputs nothing on the console window...

Note that "Enable CIO function use" is ticked.

Am I missing something obvious? 

thanks