The indexes struggled Monday, but overcame losses of as much as 1.2% to finish mostly positive. The Dow rose 0.7%. The S&P 500 added 0.5%, the NYSE composite 0.2%. The Nasdaq eased fractionally. Volume was down sharply on both major exchanges. Options expirations and the news of fraud charges against Goldman Sachs (GS) drove up Friday's trade. Stocks slid early Monday largely on the lingering negativity from the Goldman Sachs case and news from