Deleting non-music files from iPod

Hiya - little help?

I recently used my 20gb iPod as a hard drive to move some files from my old mac to my new one. I added the files to the iPod by dragging them onto the desktop icon. I then copied them to the new mac by dragging them where I wanted them. Worked fine. All up and running.

HOWEVER, to remove the files from the iPod, I opened the desktop icon folder and dragged the files to the trash. Now when I double click the desktop icon it tells me 0 items, as I expected, but the iPod summary in iTunes tells me I've still got 4gb of "other" on the iPod, as if it's all still on there but I can't see it.

How do I locate all this "other" and get rid of it? iTunes only shows audio, obviously, and the desktop iPod folder shows nothing. Where is it all?

 

**** - it WAS that! I was sure I'd done that already. Clearly I AM that useless...