How can i burn my *.flash file into the flash

You took the same trap as i did..

You have to specify the destination address in the flash while converting from .sof to .flash with

"sof2flash --input=x.sof --output=x.flash --base=0x100000" (or whatever)

At the flash-programmer you have to specify the address where the programmer can find your flash device .

This is 0x800000 on the standard altera nios2 dev boards. I don't know for nios1 designs, but if you open

them in sopc-builder you can extract this value....

nios2_flash_programmer --input=x.flash --sof=altera_nios_dev_board_cyclone_1c20.sof --base=0x800000

i hope this helps...