iPod Nano won't sync with iTunes on new laptop

When I first got my new laptop about a month ago I did the 'homesharing' technique to be able to use my iTunes on it, it worked successfully up until I tried to purchase new music from the iTunes Store & upload music into my Library from my laptop.. It just wouldn't sync onto my Nano! Every time I clicked the Sync tab nothing would happen even though the music had all been purchased/uploaded perfectly fine. I had ofcourse made sure my iTunes was 'activated' onto my new laptop, etc etc & when I went onto my old laptop to try it on there all the music DID sync onto my Nano.

Since then I've re-installed iTunes several times even copied my full iTunes folder onto an external USB stick & transferred it that way & still my Nano will not sync with my iTunes! The new iTunes isn't helping much either as I find it quite confusing to work out as it's totally different. But yeah even with the new iTunes upgrade my Nano still won't sync.

I'm at a loss, I've no idea what the problem is! Can anyone help?