multiprocessor problem

when i do a mutipprocessor test on EP2C8,Then i compiler my system and download the config file into the EPCS,finally,i download the software into sdram using the IDE,The errors occured :

Using cable "USB-Blaster [USB-0]", device 1, instance 0x02 Resetting and pausing target processor: FAILEDLeaving target processor paused .

thank you!