Sysinstall partition oddities (6.3/i386 -> 7.x/amd64)

[Steve Polyack]

I've seen some oddities with the partition and bsdlabel editors in the 
sysinstall program on the 7.0 and 7.1 releases.  The partition editor 
seems to be reading or parsing the partition table incorrectly.  I had a 
6.3-RELEASE system with the following layout:
/dev/amrd3s1a on / (ufs, local)
/dev/amrd3s1g on /opt (ufs, local, soft-updates)
/dev/amrd3s1f on /usr (ufs, local, soft-updates)
/dev/amrd3s1d on /var (ufs, local, soft-updates)
/dev/amrd3s1e on /var/log (ufs, local, soft-updates)

Upon booting into the 7.x install media and encountering the FDISK 
Partition Editor, the partition it's seeing is amrd3*a*s1, as opposed to 
amrd3s1.  Trying to continue with the partition table and bsd labels as 
is only led to the installer bailing out.  As soon as it would attempt 
to newfs the disk partitions, the installer would error and report that 
it can't find a device entry in /dev for amrd3*a*s1a.  Since preserving 
the data on the disk was not critical, I was able to continue by 
deleting the original partition/slice and recreating them.  This worked 
fine.

However, I'm still curious as to what the cause of this is.  I have seen 
this before on two other systems while installing 7.x, quite possibly 
while upgrading from 6.3.  When this occurred, I was also moving from 
i386 to amd64;  Is there some kind of offset for partition tables which 
may change based on architecture?

Lastly, here's a screenshot of the partition editor: 
http://people.collaborativefusion.com/~spolyack/fbsd-install.jpg

Unfortunately, I do not have any screenshots of the errors during the 
newfs step.  If this comes up again, I'll be sure to take some.  Thanks.