F9.5 -- HDD fails when moved to different system

[Robert Moskowitz]

Robert Moskowitz wrote:
> I have a couple of decTOPs 
> (http://www.google.com/interstitial?url=http://www.dataevolution.com/dectop%2520info%25202.htm), 
> I have had problems with these systems with Centos 5, and had to 
> perform the install on some old Compaq SFF, move the drive over, boot 
> in init 3, and run 'system-config-display --reconfig'.
>
> So after the F9 install failed to recognize the graphics card at all 
> (a geode GX2 that Centos at least saw, but did not handle right), I 
> did my F9 install on the Compaq SFF, upgraded to F9.5, and set inittab 
> to init at level 3, then moved the disk.
>
> Well the boot totally fails. What I get is about:
>
> Reading all physical volumes. This may take a while...
> No volume groups found
> Volume group "hda_00" not found
> Unable to access resume device (/dev/sda2)
> mount: error mounting /dev/root on sysroot as ext3: No such file or 
> directory
> setuproot: moving /dev failed: No such file or directory
> setuproot: error mounting /proc: No such file or directory
> setuproot: error mounting /sys: No such file or directory
> Mount failed for selinuxfs on /selinux: No such file or directory
> switchchroot: mount failed: No such file or directory
>
> And then the system hangs.
>
> I move the drive back to the Compaq SFF, and it boots. I put the drive 
> built on the decTOP but without any video back in the decTOP and it 
> boots. I move the Compaq built drive back to the decTOP and it fails 
> again.
>
> I see a couple of threads about HDD moves not working with F10, but 
> this is F9, and I can move HDDs without any problem with Centos 5. Oh, 
> I could not even build with Centos 5.2 on the decTOPs because of a 
> kernel bug in the install CD (patched later), so if I built on the 
> decTOP it was with Centos 5.1 then upgraded to 5.2, then fight with 
> the video, or build with Centos 5.2 on the Compaq and move the drive 
> then reconfig the video.
>
> Any ideas on what is going wrong here? 

After a bit more review, I see that the install on the decTOP kernel's 
ends in .i586, while the install on the Compaq SFF ends in .i686

why?