debian-installer didn't work

I believe that usb-creator-gtk may have made me a bad disk.
I tried creating the USB. The first time it said the creation failed. Then I tried it with creating a writeable partition (the first time was without).
The second time, usb-creator-gtk made the usb boot key, apparently error-free, but it won't install the system.

ProblemType: Bug
DistroRelease: Ubuntu 12.10
Package: ubiquity 2.11.23 [modified: lib/partman/automatically_partition/question]
ProcVersionSignature: Ubuntu 3.5.0-11.11-generic 3.5.2
Uname: Linux 3.5.0-11-generic x86_64
ApportVersion: 2.5.1-0ubuntu2
Architecture: amd64
CasperVersion: 1.321
Date: Sun Aug 26 18:47:15 2012
InstallCmdLine: BOOT_IMAGE=/casper/vmlinuz file=/cdrom/preseed/ubuntu.seed boot=casper quiet splash --
LiveMediaBuild: Ubuntu 12.10 "Quantal Quetzal" - Alpha amd64 (20120825)
ProcEnviron:
 TERM=unknown
 PATH=(custom, no user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: ubiquity
UpgradeStatus: No upgrade log present (probably fresh install)