Why does my iPod not registered as connected to iTunes all of the sudden?

So I got a new iPod touch (4th generation) for Christmas this year, and have had no trouble thus far syncing my music and other things to it, but recently, when I plug my device into my computer, iTunes does not register that it is plugged in, but my computer does....I have run out of option, and have even restored my iPod completely, hoping that would help, but nothing has worked and now I have lost everything on my iPod alltogether. I have grown frustrated and need assistance with this as soon as possible.