Fedora 13 install partitioning issue

[David Jansen]

I ran into an issue with the installation of Fedora 13. What I was
trying to do was this: install the new version, choose for a custom
layout of the partitions, and then have system stuff like / and /usr
reformatted, but leave /usr/local, /opt, /home and /data partitions
alone to preserve own data and software not installed from rpms.
This is how I have done system upgrades/reinstalls fro years. 

However, with Fedora 13, when I choose the custom install, all my
partitions are marked as type "unknown" and all I can do is select them
and format them, or abort the installation (which I did, of course).
This happens to all partitions, ext3, ext4, swap, and ntfs.

Is this a known issue (couldn't find anything about it), a boot option I
have missed, or perhaps something specific to the 2 computers where I
tried the installation ??

If these partitions were on another disk, I understand I can skip the
disk as a data storage disk which isn't used in partitioning, but
unfortunately, it's not on a separate disk. So, what to do?

David Jansen