USB Natty alpha images fail to boot

Binary package hint: syslinux

Toshiba Satellite C650D.

Created USB image of Natty Alpha 1 from my desktop (Lucid) machine as per http://www.jonobacon.org/2010/11/30/testing-natty-and-unity-safely-with-a-usb-stick/ .

Reboot, get SYSLINUX line and it hangs there.

ProblemType: Bug
DistroRelease: Ubuntu 10.10
Package: syslinux 2:4.01+dfsg-3ubuntu1
ProcVersionSignature: Ubuntu 2.6.35-23.41-generic-pae 2.6.35.7
Uname: Linux 2.6.35-23-generic-pae i686
NonfreeKernelModules: nvidia
Architecture: i386
Date: Fri Dec 3 09:56:07 2010
InstallationMedia: Kubuntu 9.10 "Karmic Koala" - Release i386 (20091028.5)
ProcEnviron:
 PATH=(custom, user)
 LANG=en_GB.utf8
 SHELL=/bin/bash
SourcePackage: syslinux