When you import into iTunes it will probably be converting all of your music to mp3 or AAC. What I did since I wanted all mine as mp3's was to add them to the library instead of importing. Then I selected all and selected creat mp3 version. I let the computer run forever while it did this and then at the end the original ones I had selected were still highlighted so I right clicked and deleted all those. After this process I was left with all of my music in mp3 form. Not very convenient but it worked.