Desperate after upgrading OBP from 3.11 to 3.31

Hello all,

I've upgraded my OBP from 3.11 to 3.31 and now my SUN won't boot 
anymore. Whatever I try at the 'ok' prompt has no effect, it keeps 
saying 'The file just loaded does not appear to be executable'. I've 
tried pretty much all versions of 'boot disk#:#' by now. The system in 
question is a SUN Ultra10, 300MHz, 320MB RAM, 40GB HD Maxtor 6E040L.

Partition layout:

<snip>
Disk /dev/ide/host0/bus0/target0/lun0/disc (Sun disk label): 16 heads, 
63 sectors, 16383 cylinders
Units = cylinders of 1008 * 512 bytes

                                 Device Flag    Start       End 
Blocks   Id  System
/dev/ide/host0/bus0/target0/lun0/part1             1       101     50400 
   83  Linux native
/dev/ide/host0/bus0/target0/lun0/part2           101     79144  39837672 
   83  Linux native
/dev/ide/host0/bus0/target0/lun0/part3             0     79656  40146624 
    5  Whole disk
/dev/ide/host0/bus0/target0/lun0/part4  u      79147     79655    256032 
   82  Linux swap

Disk /dev/ide/host0/bus0/target0/lun0/part3 (Sun disk label): 16 heads, 
63 sectors, 16383 cylinders
Units = cylinders of 1008 * 512 bytes

                                  Device Flag    Start       End 
Blocks   Id  System
/dev/ide/host0/bus0/target0/lun0/part3p1             1       101 
50400   83  Linux native
/dev/ide/host0/bus0/target0/lun0/part3p2           101     79144 
39837672   83  Linux native
/dev/ide/host0/bus0/target0/lun0/part3p3             0     79656 
40146624    5  Whole disk
/dev/ide/host0/bus0/target0/lun0/part3p4  u      79147     79655 
256032   82  Linux swap
</snip>

As you can see, I can boot fine from CD...

My SILO configuration:

<snip>
partition=1
root=/dev/hda2
timeout
device=/dev/hda
image=/boot/2.6.12
         label=linux
image=/boot/2.6.12-old
         label=old
</snip>

This is all correct:

<snip>
livecd ~ # ls /boot/
2.6.12      System.map         System.map-2.6.12-old  fd.b     generic.b 
  isofs.b     old.b     silo.conf   ultra.b
2.6.12-old  System.map-2.6.12  boot                   first.b  ieee32.b 
   lost+found  second.b  silotftp.b
</snip>

Running SILO yields no errors... Can someone please help? There has to 
be a simple way of fixing this, and I really don't believe I'm the only 
one who has ever had this problem either. I've already spent 5(!) hours 
reading every single search result I could find on Google and on the 
Gentoo forums about this... My SUN is pretty much dead in the water 
right now, as I don't feel like booting from a LiveCD just to get it 
beyond the OpenBoot POST.

Kind regards,

Arnim Eijkhoudt