At home is where I keep my major music collection where I rip everything in my collection to HD.
Then instead of sucking up all that precious CPU, I just copy over the music I want (the folders inside the iTunes music folder) to my iBook that I take to work, and drag it onto a playlist or to the library.
Now, for some strange reason, iTunes decides that randomly, when I drag a folder with the music (let's say Nickelback for instance), it will import it twice... and sometimes not in the same way.
For example... It will make straight up duplicates in the music folder as in ".mp3" and "1.mp3."
Other times it will have it duplicated in the library list, but both items point to the same file....
And other times it just imports fine.
Why do I have to do the duplicate dance? Does my iTunes have a split personality?