NAND read: device 0 offset 0x2d8000, size 0x300000
nand erase 0x2d4000 0x2f000
nand write.e 0x12000000 0x2d4000 0x2f0000
You are flashing it at another address as where u-boot tries to read it. And u-boot also uses a bigger size. (That size is not really important, as long as it's 'big enough'. The uImage header is read *after* it is copied to ram, and contains the real size.)
Now you have two possibilities:
- Change the address for the initrd in the u-boot environment. (printenv, setenv and saveenv are the keywords, together with 'help')
- Flash the images on the place where u-boot expects them.
Don't know where you got your flash instructions. If they are explicitely for the ix4-200D, then some point in time Iomega changed the flash division. And of course there is a reason for that. The flash is 32MB, and u-boot reads it up to 0x2b8000+0x300000=0x5b8000=5996544 ~6MB.
The other 26MB is used to contain the firmware which is meant to be installed on the harddisk. I guess that for the CE edition this was narrow, for which reason 'they' removed some slackspace from the lower addresses. Although that won't give more than a few hundred kB.