I have compiled some pretty amazing statistics over my play at PS (I use PokerTracker). They are really amazing - out of the last 30 times I was involved in All-in, when the odds were approximately 50/50, I lost every single time. My winrate statistic is fully 20 percent lower on Stars than on other sites. Well, at least they are consistent - when they decide to screw you, they don't give up. I finally withdrew what is left of my money and will never play there again.
Pokerstars is most definitely rigged.