US STOCKS-Dow posts best month in 2011 but Microsoft drags
April 29, 2011 at 16:26 PM EDT
* Caterpillar leads industrials higher on results, outlook * Microsoft falls on earnings, RIM tumbles after outlook * Nasdaq posts eighth straight day of gains * Dow up 0.4 pct, S&P up 0.2 pct, Nasdaq up 0.04 pct