grub-setup: error: Non-sector-aligned data is found in the core file

[UrJiZ]

I've been working on a project of mine, putting GRUB2 to An award BIOS
using ROMOS (http://rayer.ic.cz/romos/romose.htm).
I've succesfully compiled GRUB 2 and generated my first rom disk
image. I used http://grub.enbug.org/TestingOnX86 ,"Creating the
Floppy" as my guide. I followed it mostly but skipping the copying of
all the mods to the image (no space in 62K for 'em),  but adding all
the necesary modules to the core.img.
The succesfull core.img was created using the following command:
./grub-mkimage -d . -v -o core.img biosdisk configfile terminal normal
_chain fat linux ext2 ls font halt pc

The disk had 5.5K of free space on this version, and I as I saw ata.c,
i thought that it could also support CD's by adding ata and iso9660.
So, a new core.img was created like so:
./grub-mkimage -d . -v -o core.img biosdisk configfile terminal normal
_chain fat linux ext2 ls font halt pc ata iso9660

This core.img was a little bit larger, left 1K of free on the disk
(good for grub.cfg when all else is done).
This time grub-setup failed with the error on the subject line. I
googled for it and found nothing, so i thought i could ask here about
it.

So, why is this a problem, and why it worked for the first time but
not with 2 more modules?...

-- 
urjaman