Maybe some kind of memory error try to zeroise device(note it takes about an hour or so)

refer to here: http://talk.maemo.org/showthread.php?t=82693

side note(s):
DFL61_HARMATTAN_40.2012.21-3_PR_LEGACY_001-OEM1-958_ARM.bin is your main.bin

and

DFL61_HARMATTAN_40.2012.13-7.LTA_EMMC_LTA.bin is your emmc.bin

(i think you already know this but its better if you name them that way (i did and it made flashing easier to type in))