6.10 install erased my LVM volumes

First a little history. I've been a Linux user since 1995. I've heard such good things about Ubuntu I thought I would switch from Fedora Core 6. I've been running FC6 on an LVM partition for months. I noticed here that you need to download and boot from an alternative CD, so I downloaded Feisty-alt. (BTW, the 30 minute wait for it to find the LVM volumes really sucks.) No luck. I didn't install Grub since it was already installed, and just modified the existing grub.conf. After rebooting it uncompressed vmlinuz but soon after it hung. I rebooted FC6 and it was OK.

I figured I had enough normal partition space to try the standard desktop CD, so I downloaded 6.10 live. I did an apt-get on lvm2 just in case the install program might find my LVM volumes. No luck again, but I proceeded with the install. I chose to install Grub on one of the partitions since there didn't appear to be an option not to install it, and I didn't want to overwrite the existing one. BTW this partition was on hda and my LVM was on hdb. The installation proceeded and finished. I had to reboot to FC6 to play with grub.conf, so I tried that.

FC6 tried to boot but reported that it couldn't locate any LVM volumes. I booted my FC7 live CD and it can find the physical volume, but there are no logical volumes. My entire FC6 is wiped out. Luckily I made a backup of my /home directories, but it will be a pain to rebuild everything.

Disk partition info:

hda
  1 - NTFS Windows installation
  2 - ext3 FC6 boot
  3 - unused Linux partition
  4 - extended partition
    5 - unused Linux
    6 - unused Linux - told Ubuntu to install grub here

hdb
  1 FAT32 Windows
  2 Linux 10 Gig - used to install 6.10
  3 Swap
  4 LVM partition
     00 - FC6 /home
     01 - unused
     02 - unused
     04 - FC6 /usr
     05 - FC6 /
     06 - unused