<<help>> my iPod in my iPhone won't work

Hello, I have a serious problem, I'm getting mad lol but I got a iPhone 3GS and my iPod won't work, it keeps on freezing up and going back to the main screen :( I downloaded the new version 4.0.1 on iTunes and that's when it happened. Is there anybody know how to resolve this without syncing it, I'm too scared to erase all my songs..you know how that is redownload over 2000 songs all over again lol.

I appreciate alot thank you :)