Because it is a 128KB file and not a 256KB file you must use
the 128 in commands while flashing or backing up
-flash:cfe128 /noemw /noreset or -backup:cfe128 /noemw /noreset 

tjtag -flash:cfe128 /noreset 

This is for DD-WRT firmware only micro or micro plus.
This will not work with the Linksys firmware.