Comment 3 for bug 446035

According to a songbird forum, it's because the iPod isn't mounted at the right place. Here is a work around FIX, from the forum:

     "It mainly involves using the terminal to unmount and remount the device to another directory. I believe the problems we are having is due to the migration from udev to devkit in ubuntu karmic.

     (First EJECT your iPod, then...) For example your ipod is the block device /dev/sdb1 so I would do the following.

     sudo -i #(this drops you into a root shell)
     mkdir /mnt/ipod #(you can use any directory really but this is easy to remember.)
     mount -t vfat -o rw,uid=1000,gid=1000,utf8=1,dmask=0077,flush /dev/sdb1 /mnt/ipod

     (this mounts a vfat filesystem on device /dev/sdb1 to directory /mnt/ipod owned by the user and group who's ID number is 1000, utf8 support is enabled and all changes are written to disk immediately. Substitute 1000 for the UID and GID of your user and the group your user is in)"

After doing this, gtkpod correctly reconize and load the ipod.
source: http://getsatisfaction.com/songbird/topics/ipod_not_connecting_on_ubuntu_karmic_9_10

UPDATE: I'm also tested a second FIX: I added another gtkpod ipod repository, targeted to the correct mount point of the ipod. This also worked BUT I have to manually hit the "Load iPod" on gtkpod to make this easier fix work.