Comment 17 for bug 539324

I managed to work around this bug by letting the installer set up full-disk encryption as usual. When the error message came, I chose "Yes" to display the partitioning scheme already created by the installer. Here I changed the type of the swap partition from "swap" to "do not use". The installation completed successfully after that.

Then, right after first booting into the new system, I manually turned the unused partition (named /dev/<hostname>/swap_1) into a proper swap partition by following these instructions:

http://www.linux.com/news/software/applications/8208-all-about-linux-swap-space

Entering two commands (mkswap, swapon) at the terminal, adding the swap partition to /etc/fstab and testing the whole thing by rebooting the computer took just a couple of minutes.