[CentOS] CentOS 5 upgrade from 4.4 fails. Cannot mount /dev/md1 root partition

Have completed two clean installs of CentOS 5 with no issues (other than
permissions on ~/.ssh directory.  One 32 bit system, one 64 bit.  When I
tried an upgrade from 4.4 on 64 bit system with two SATA drives in Raid
1 configuration, anaconda could not mount the root partition /dev/md1.
The error message suggested it was because the partition was not
formated which is obviously not correct.

Any thoughts appreciated. Thanks in advance.

B.J. McClure

CentOS 4.4, Linux 2.6.9-42.0.10.ELsmp x86_64 19:37:58 up 10 min, 2
users, load average: 0.10, 0.19, 0.14