Ubiquity crashes during installation of Mythbuntu 14.04

This happens on both the 32-bit and 64-bit versions of mythbuntu 14.04. The installer gets near the end, and crashes. The only workaround that I've had success with is to install Mythbuntu 12.04 and then do the upgrades to 14.04. I've had this issue since Mythbuntu 14.04 was originally released. Also I should note that I just downloaded and burned the DVD today (at the lowest speed setting for my drive).

ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: ubiquity 2.18.7
ProcVersionSignature: Ubuntu 3.13.0-24.46-generic 3.13.9
Uname: Linux 3.13.0-24-generic x86_64
ApportVersion: 2.14.1-0ubuntu3
Architecture: amd64
CasperVersion: 1.340
Date: Fri Jun 13 09:07:25 2014
InstallCmdLine: file=/cdrom/preseed/mythbuntu.seed boot=casper only-ubiquity initrd=/casper/initrd.lz quiet splash -- nomodeset
LiveMediaBuild: Mythbuntu 14.04 LTS "Trusty Tahr" - Release amd64 (20140417)
ProcEnviron:
 TERM=linux
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_US.UTF-8
SourcePackage: ubiquity
UpgradeStatus: No upgrade log present (probably fresh install)