Whether it is some traders trying to "screw" us, or some traders simply playing the technicals, I think you can rest assured that PRB is in an uptrend and this small decline forms part of a pattern.

If you see by the following chart, everytime PRB hits the upward bollinger band (green), it retreats somewhat before either going sideways and then back up or simply straight back up. You can also see by the chart that we are well above the 50, 100, and 200 day moving averages.

http://finance.yahoo.com/echarts?s=PRB.V+Interactive#symbol=prb.v;range=2y;compare=;indicator=sma(50,100,200)+bollinger+volume+macd;charttype=area;crosshair=on;ohlcvalues=0;logscale=off;source=;

Here is another look at the technicals and how positive they are right now for PRB:

http://www.stockta.com/cgi-bin/analysis.pl?symb=PRB.C&cobrand=&mode=stock