Ejects itself from iTunes library.

It sounds like there is a bug in the firmware you have on your iPod. I've had something similar happen to me, and to fix it I've just restarted the iPod (turn on hold, count to five, turn off hold, press and hold the center button and the menu button till it reboots).

If you reboot both your computer and your iPod and it still doesn't come out of the do not disconnect state, then you should make sure all of your music is backed up off of your iPod onto your computer and use the factory reset button in itunes to reinstall the software to your iPod.

I hope that helps.