If you repartition a disk completely with disk druid, then go through package selection and select too much stuff to fit, you will get a warning, then get sent back to try again. If you then just go forwards again to where it will start to try to install packages, you will get an error saying it could not reread the partition table. This is because something is holding the device open. Also, when you click 'ok' at the error screen you get informing you of this problem, the installer exits abnormally instead of rebooting cleanly.
This defect is considered MUST-FIX for Florence Release-Candidate #1
*** Bug 25165 has been marked as a duplicate of this bug. ***
This happens because we have turned on swap, and can't turn it off because on some machines we need swap for install to continue. Need to check and see if we need to rewrite partition table when they have gone back and tried to make more space. If they just removed packages to make space, we don't save partition table. If they modified partition table then they'll have to reboot because the drive(s) with swap enabled are busy and we can't reread the partition table.