I have this problem too; it says "no root filesystem" if I've made partition (ext2/ext3) before the installation using another app (GParted or QParted for example). The selected root partition needs to be reformated or deleted and then made again.
-- mount points preparation locked - "No root file system" https://launchpad.net/bugs/67130 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
