BEN AFFLECK -- DOWN 'N' DIRTY IN VEGAS

NOT AFFLECK-TIONATE:

What the HELL happened to "Gentle Ben" Affleck -- a legendary great tipper at casinos?? Fresh from "Pearl Harbor," Ben hit Montreal to film "Sum of All Fears" and was a sweetheart on the set -- then turned into a foulmouthed, belligerent jerk, insulting patrons at a casino and flinging cards in a dealer's kisser! A spywitness said, "Ben was like Dr. Jekyll and Mr. Hyde. He was buying $5,000 chips and downing house drinks . . . and his foul language wasn't going over well. He was down about $70,000 and he got louder, picking on the poor dealer, saying, 'Would it kill ya to deal an EFF-ING BLACKJACK once in a while?' Other players started riding him . . . and he told them 'EFF OFF!' I thought they'd come to blows. On his last hand, he threw his cards in the dealer's face and walked off -- and people were clapping and jeering!"