Error while downloading .sof for linux_1c20

while downmloading the .sof of the linux_1c20 project on FPGA

after programming is 100% complete it gives error message :

Can't communicate with device. and loads the FPGA with factory image.

I have tried to download same using Quartus II 5.0 and 5.1 programmer but the error persists.

I am able to download all other .sof other than this one.

Though Nios2 is time limited opencore I am not closing the message window that appears after downloading.Even after flashing the error message the window remains.

What must be the problem?