Just before lunchtime last Tuesday, the Dow Jones industrial average was ahead more than 30 points and was again nudging up against its all-time high.</br></br>But by the time stock traders were leaving work that day, the widely followed indicator of blue-chip stock performance was tenuously holding just a 7-point gain. What happened?</br></br>Nothing, except that the Dow for the fifth time since it reached an all-time high in early June had tried and failed to climb beyond the record.</br></br>It is entirely possible that the Dow will reach new heights in the days or weeks ahead. Several other indexes are already in the stratosphere, and all it will take is a burst of well-timed program trading to lift the Dow to record levels.</br></br>But record or no record, many Wall Street experts are bothered by the fact that the Dow is moving ahead with so little conviction. Program trading - the computerized buying of stocks as an arbitrage play against stock index futures contracts - doesn't count. They want to see stocks rise because stocks deserve to rise.