From the wrap manual
http://www.pcengines.ch/pdf/wrap1c.pdfCompactFlash partitioning
tinyBIOS is set up to configure the CF card in CHS mode. CHS mode is dependent on the
geometry of the CF card, but is more likely to work consistently across systems.
If using LBA mode, please make sure that the disk geometry on the system where the card is
initialized matches that shown by the WRAP BIOS during startup. A mismatch will cause problems.
one could try configuring the C/H/S on the host to match the geometry displayed on the wrap bios screen, and then writing the image to flash.