Banshee System.NullReferenceException while syncing

[JanCeuleers]

Podcasts are not being synced to my ipod (30GB 4th gen). That is: Banshee's GUI says that it transfers the files across, but then they do not show up in the Podcasts menu, neither in Banshee nor on the device itself. Please refer to the debug output: this is the full output of banshee --debug; towards the end of the file there are lots of instances of the following:

[18 Warn 08:37:28.597] Cannot save track to the Apple device - System.NullReferenceException: Object reference not set to an instance of an object (in `Banshee.Dap.AppleDevice')
  at Banshee.Dap.AppleDevice.AppleDeviceTrackInfo.CommitToIpod (GPod.ITDB database) [0x00000] in <filename unknown>:0
  at Banshee.Dap.AppleDevice.AppleDeviceSource.PerformSyncThreadCycle () [0x00000] in <filename unknown>:0

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: banshee 2.4.0-2ubuntu1
ProcVersionSignature: Ubuntu 3.2.0-25.40-generic 3.2.18
Uname: Linux 3.2.0-25-generic x86_64
NonfreeKernelModules: fglrx
ApportVersion: 2.0.1-0ubuntu8
Architecture: amd64
Date: Tue Jun 19 08:38:40 2012
InstallationMedia: Ubuntu 12.04 LTS "Precise Pangolin" - Release amd64 (20120425)
ProcEnviron:
 TERM=xterm
 PATH=(custom, no user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: banshee
UpgradeStatus: No upgrade log present (probably fresh install)