need help with extracting u-boot.bin

[Lorcan]

Hey,

got myself a iriver cover story a few months ago.
would like to hack the thing, since it's linux based.
however, except for some *.feb files , the zImage en u-boot.bin
everything was a success.  The zImage is almost complete, but the u-boot.bin
is a problem.

/opt/firmware-mod-kit/trunk/extract-firmware.sh u-boot.bin
Firmware Mod Kit (extract) 0.99, (c)2011-2013 Craig Heffner, Jeremy Collake

Preparing tools ...
mksquashfs.c: In function ‘reader_scan’:
mksquashfs.c:2005:2: warning: ‘return’ with a value, in function returning void [enabled by default]
Scanning firmware...

Scan Time:     2013-07-09 21:03:41
Signatures:    193
Target File:   /StoryEB05/u-boot.bin
MD5 Checksum:  3b5d3c7d207e37dceeedd301e35e2e58

DECIMAL      HEX          DESCRIPTION
-------------------------------------------------------------------------------------------------------

Extracting 0 bytes of  header image at offset 0
ERROR: No supported file system found! Aborting...

when typing;
file u-boot.bin

it return this;
u-boot.bin: data


anyone know how to decompress the damn file?
thanks in advance
L