Cover art images are not correctly generated on iPod Classic (2009 series), they are not displayed on the iPod.
Tests on gtkpod 0.99.14 on Ubuntu Karmic, iPod Classic 2009 160Gb:
1- format (restore) iPod (using iTunes on Mac OS)
2- disk utility: disable HFS journaling
3- add one track in iTunes
4- on Linux: modify SysInfo (add FireWireGUID)
5- gtkpod: add track
6- save -> iPod_Control/Artwork/ is modified
7- eject ipod and test
The files (ArtworkDB and .ithmb) in the directory iPod_Control/Artwork/ are modified.
Sometimes, the ipod display a garbage image (black/white random pattern), and sometimes no image at all.