my sympathies, Dayv I got the same thing at my work place. A manager at my place is the son of a higher manager's best friend. That guy can get away with murder. No matter what he does(doesn't do as the case be) or however many mistakes he makes, nothing happens to him. I can't stand him. I'm just glas I don't work directly under him.
My manager hates him too and so does just about everyone else there, but there's nothing anyone can do.

let me just give you a few examples of his fine work ethic:

He's been caught sleeping on the job.
He been rude to customers.
He's lost important files.
He's shown up extremely late to work(many, many times).
He leave's work very,very, early(again many, many times).
He's shown up to work very, very hung over.
He's appeared drunk in front of customers.
He's disobeyed direct orders of superiors.
Half of my manager's day is taken up with doing the work that should be done by the this guy.
Just this week he broke a very important regulation at our customer's place of business and left us open to a very heavy fine.