I have not heard this problem before, at least as far as plugging in an iPod is concerned, but I suspect you may have a virus of some sort. You do not give any details of your equipment but I'm assuming you use Windows.
You also do not say if iTunes opens when you plug in your ipod (This can be switched on or off in iTunes preferences. If so check out this post
http://www.gnutellaforums.com/showthread.php?t=41432 At the end of the post is a link to Norbies world who are most helpful.
I hope you have and run a constantly updated anti virus programme. This is vital if using any internet applications and especially p2p.
If you are running Mac OSX you can ignore most of what I said, and I would have to say I'm puzzled
