MINYANVILLE ORIGINAL Christmas may be over but investors are still on the watch for the traditional Santa rally with stocks edging down after a worrying holiday shopping report from retailers.   Sales for the season are expected to increase only around 0.7% compared to forecasts for a 2%-3% increase with shoppers cutting spending because of fiscal cliff worries.   The Nasdaq Composite (INDEXNASDAQ:.IXIC) was down 0.76% to 2 989.63 points on incredibly anemic volume of 435.30 million as of 12:11 p.m. EST. Research In Motion (NASDAQ:RIMM) helped to lift the Nasdaq jumping a robust 7.45% to $11.40.   Zynga (NASDAQ:ZNGA) (+2.58% to $2.39) ...