I finally got time to test my solution on an ALIX board and indeed it crashes.
I found out at least to mistakes so far.
First the initrd.gz is a copy from the iso image and therefore only checks media type cdrom, which is not the case of CF card or harddisk.
Therefore you never load from the disk the root partition.
Second and worst, it seems I must have forgotten the iso9660 compressed file system within the kernel.
So eventhough you correct first mistake you will be stuck by the second.
I will supply a new version tomorrow and publish it online on my website at http://www.hbar.ch under the zeroshell structure.