Yeah, there was the Katich incident. After a victory Clarke wanted to head off to a media engagement without singing the team song in the dressing room.
Simon Katich took exception and ended up grabbing him by the throat, and rumour has it Clarke then worked to blackball him from the side over time.
There is a long-standing belief in Australia that the selectors favour players from New South Wales, it's particularly prevalent here in Western Australia. The likes of the Lee brothers etc.
There's also the problem that players who present well in the media get larger contracts and exposure they don't deserve. Used to be the one-day "stars" who weren't up to Test standard, like Simon O'Donnell. Clarke's far more gifted than O'Donnell ever was, but his pretty boy image and WAG issues haven't helped.