Please try running 'sudo apt-get update; sudo apt-get install ubiquity' from a terminal window on the live CD before starting the installer. This is almost certainly bug 94647 or bug 95400, both of which are fixed now.
-- Unable to resize partition (feisty beta) https://launchpad.net/bugs/97545 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
