Step 5 of install fails

[Tom H]

On Thu, Sep 16, 2010 at 1:22 AM, Doug <dmcgarrett at optonline.net> wrote:
> When I get to step 5 of the install (Ubuntu 10.04 or 10.04.1 for
> Desktop-i386) there is supposed to be a way to select a partition, but
> it doesn't work.  The only option is to wipe the disk.  I want to
> install to an extended partition,
> /dev/sda9, which starts at 10761 and ends at 14075, and is formatted
> type 83, Linux.  It is otherwise empty.  On this machine there are XP,
> PcLinuxOs, and Debian Squeeze, all accessed by Grub, and they all work.
> How can I add Ubuntu to the stew?

Is the partition already "carved out"?

Are you choosing "specify partitions manually" at the "disk space" step?