You don't say if you are using Mint 4.0 or 5.0. I'm also assuming this is a pretty recent iPod model.
I had this exact same problem with my nano 3G (a fatty) and it is easy to fix. The problem is caused by Apple using a hash to keep 3rd party apps from working with iPods.
See this post in the Amarok wiki for a solution:http://amarok.kde.org/wiki/Media_Device ... _any_music
I did this and now my nano 3G works just fine Mint 5.0.