flash programmer error

hello everyone:

I want to use flash programmer in NiodII IDE to program a file into flash.

But the program process is not stable.Sometimes the process failed when it had programmed 61%,sometime the process failed when it had programmed 3%..

below is a segment of the error message:

000E0000 (53%): Programming

000F0000 (57%): Programming

00100000 (61%): Programming

Program failed at offset 101504

Leaving target processor paused

Does anyone have suggestions about this phenomenon? By the way, I use Byteblaster,and the version of quartus and nios II is 6.0.

Thanks!

0quanquan0