I lived in the Veneto for 4 years, and I would say the north is definitely corrupt. I've seen business people turning up at the commune to hand over bags full of cash without uttering a single word. Places of business burnt down because they the owners didn't have "approval" from the right people. Council officials just blatantly asking for money to make something happen. Try buying a house in the Veneto, you have to do it illegally.

Also, I bumped into a lot of Lega Nord people (the secessionist party) while I lived there and generally found them to be little more than racists and fascists. When I had to obtain my Permesso di Soggiorno, a group of us, all english turned up on the same day. We were all given 2 year stamps, except my black friend. They would only give him 6 months. I found the north of Italy to be jaw dropingly racist across the board.

At least, that was my experience. Don't get me wrong, I love Italy, but it's only because I let myself be blissfully ignorant of it's fundamental flaws when I'm there.