iPhone 4S - "Unsupported checksum type " when trying to sync

I am getting a Unsupported checksum type message when trying to sync my iPhone 4S. My older iPod Touch worked just fine...

I would expect the newer device to work as well.

gtkpod:
  Installed: 2.1.1-1
  Candidate: 2.1.1-1
  Version table:
 *** 2.1.1-1 0
        500 http://us.archive.ubuntu.com/ubuntu/ precise/universe amd64 Packages
        100 /var/lib/dpkg/status

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: gtkpod 2.1.1-1
ProcVersionSignature: Ubuntu 3.2.0-19.30-generic 3.2.11
Uname: Linux 3.2.0-19-generic x86_64
NonfreeKernelModules: nvidia wl
ApportVersion: 1.94.1-0ubuntu2
Architecture: amd64
Date: Mon Mar 19 18:19:09 2012
InstallationMedia: Ubuntu 11.10 "Oneiric Ocelot" - Release amd64 (20111012)
ProcEnviron:
 TERM=xterm
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: gtkpod
UpgradeStatus: Upgraded to precise on 2012-03-02 (17 days ago)