I assume by 9.10 you mean Ubuntu? (Or maybe Kubuntu or Xubuntu or Edubuntu....) Anyway, do you have gtkpod or gtkpod-aac? From the gtkpod-aac package description:
This gtkpod version has been build with aac and mp4 support.
. I don't use an ipod personally, so I don't know if this makes a difference, but I do know that these are 2 separate packages.