I don't know about the model C700, but some of the older Zaurus models need to be flashed with the files on a CF card, not SD card.
I cannot remember where I read this, (about CF vs. SD flashing) but it has been discussed before.
I have always used a CF card to flash both of my Zauri, (C3100 and C3200)
I don't know about the C700, but I haven't ever seen the file called "zimabe"
My CF card used to flash Cacko 1.23 has these 3 files in the root of the card:
initrd.bin
tools.tar
update.sh
For pdaxii13, I also have another CF card with the same named files as the above example for Cacko, (except these are pdaxii13 files).
When using a CF card to flash, make sure it is formatted as FAT 16