help: data read from not same as the *.flash file(elf2flash),why?

hi,

my flash only included nios program(elf2flash), configuration data(sof2flash) was in epcs. when Por, the program is run in the course of nature. and then read from flash, i found that the data of flash was not the same as the *.flash(elf2flash). i don't know why.

http://www.alteraforum.com/forum//proweb/misc/progress.gif