Could you attach /var/log/syslog and /var/log/partman as that will allow the issue to be further investigated. For more information you can look at the wiki page that deals with debugging ubiquity: https://wiki.ubuntu.com/DebuggingUbiquity .
Thanks, Brian -- installer hangs in feisty https://launchpad.net/bugs/77292 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
