ITunes problem

I have been using my iPod touch for a while now and it has been fine with iTunes. Then it wanted me to upgrade to version 10 or something like that so I upgraded it installed etc and now when I go on to iTunes the toolbar and the bar down the left hand side goes dull in colour and I can't do anything it won't sync it wnt do anything but when i download I have to do it on iPod touch and some if the songs say download error tap to retry so I can't do that now either so I am stuck :/