Problems for run nios applications in hardware

The board I used is "Stratix II EP2S60 DSP development board".

When I am trying to run a small program in this board, I meet the following

problems:

Using cable "USB-Blaster [USB-0]", device 1, instance 0x00

Pausing target processor: not responding.

Resetting and trying again: FAILED

Leaving target processor paused

Anybody know how to fix it? Thanks a lot!!

Ruling.