And I've heared!
As for Dent I don't remember when it was but he was absolutely mad when he wasn't agree with the umpire's decision. He said really nasty things!
The same sometimes happens to Andy or Lley
Well and the champion IMO is Sharapova. Saw her at KC. Not a single autograph! She was always surrounded by a dozen of guards and not even looking at her fans (including cute little kids!) asking for an autograph!