iTunes cancelling sync automatically.

So I upgrade my iPhone to iOS 5 like everyone else would, it downloaded okay, and i thought all was good as I started to set it up. iTunes was restoring my iPhone like it normally would, suddenly, iTunes pops up with 'restore interrupted' or something along those lines and gives me a choice to stop the restoration or keep going. So I keep going, and it comes up with 'error -51'. Now I've done research and nobody seems to have found a legitamate answer. Also, I try to sync my phone and I've never had a problem until iTunes 10.5 and iOS 5, this time, while the steps are going, steps 1,2 & 3 are fine with the determing of tracks and everything until it suddenly comes up with 'Safari Browser Safe Page' and then suddenly for a split second 'Cancelling sync' pops up and that's it.

Can anyone please help me with this? It would be muchly appreciated.