This is a known problem in the KDE frontend. Jonathan, there's a TODO comment from me in the code (set_autopartition_choices) if you wouldn't mind having a look ...
** Changed in: ubiquity (Ubuntu)
Status: Unconfirmed => Confirmed
--
prepare disk space contains "usertrap"
https://launchpad.net/bugs/85980
--
ubuntu-bugs mailing list
ubuntu-bugs@lists.ubuntu.com
https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
