IPOD NOT REGISTERING IN ITUNES

Hello,



I have an ipod classic which my itunes will not register. It is registering on my pc and I have tried doing scans which says the device is working fine. A friend of mine recently plugged my ipod into his mac computer which I soon after discovered basically deletes the music and can corrupt the files. It did this but since then it has fixed itself, somehow. (I have no idea how, but one day it started working.) Now it is not registering in itunes again. All it says on the screen is "Connected- eject before disconnecting" but I cannot even do anything. I have restarted, restored, and even gone into disk mode. Nothing is working. IT IS VERY FRUSTRATING!!!!!!! PLEASE HELP!!!!!!!