Chico, try the following PBs (if you use QT) on your NQ chart and tell me how it compares with your 8/17/9 MACD crossover. Essentially it is the first dirivative of the histogram and therefore changes as the distance between the moving averages changes:
if MACD(12,26,9).Histogram>MACD(12,26,9).Histogram[1] set color to Green
if MACD(12,26,9).Histogram<MACD(12,26,9).Histogram[1] set color to Maroon
Murray