Darko sent me a link to a blog post about a serious PokerStars error. Supposedly, a tourney was canceled because there were 5 Aces in the hand in a Hold'em game! Check out the link for the screenshot.
I tend to think this is a Photoshop job because if the software couldn't keep track of which cards had already been dealt, we'd see consistent errors in the billions of hands that have been dealt out since the PokerStars launch. But this is the first time I've heard of an issue like this. I would think this would be major online news if this was true.