One third of the float is sold short.. Do you think these shorts want to let the price get out of hand before they're ready to cover? Many (e.g. Soros) are long the stock and have heavily shorted against the box. When the time comes they will cover and take profit on the long side, taking advantage of the momentum fueled by their covering.
Market makers with naked shorting power are holding it down as best they can (there is a lot of upward pressure) until after the Russell rebalance at the end of the week. Many index funds have to buy in and the mechanisms of the market are supposed to prevent an upward bubble in this situation. They do this by shorting the stock when it gets too boisterous. All this goes mechanism goes away next week and there should be much clearer waters ahead.
The only reason for it is because we'd be lost on the message board without your whiny posts everyday. The stock will never close above $40 until you disappear for good. Once you leave, the $30s will be gone. So it's up to you. You hold the direction of the price in your hands. Are you going to be selfish and stick around or are you going to leave permanently?