Canadian Solar (NASDAQ:CSIQ) shares have been dropped like a dead-end murder investigation. Let's put on our forensic fedoras and try to figure out what Mr. Market didn't like about CSI's earnings report.

Sequential top-line growth, at 24%, approximated that achieved by Yingli Green Energy (NYSE:YGE) in its own gleeful quarter. Shipments were up a more modest 13%. Earnings results were distorted a bit by debtholders' conversion of notes into common stock, but we're no strangers to such accounting quirks in solar land.

CSI is building out its capacity at a brisk pace. Year-end cell capacity should hit 400 megawatts (MW), while module capacity ought to crack 600 MW. As long as the latter outpaces the former, the company will continue to bridge the gap by purchasing cells from other companies like JA Solar (NASDAQ:JASO).

To give a sense of where Canadian Solar weighs in, contrast the company's 2009 guidance of 550 to 500 MW shipped to SunPower's (NASDAQ:SPWR) 450+ MW of projected capacity next year. (Capacity alone doth not a shipment make.) The two firms are not directly comparable, as SunPower plays in a higher-efficiency, higher-margin sandbox, but the difference in market capitalization -- SunPower’s is nearly seven times higher -- is still pretty startling.

Which brings us back to the matter of why CSI's in the dumps. The quarterly results didn't disappoint in any discernible way.

One factor that may weigh on shares is the specter of future dilution. CSI stated that it has adequate funding for the second half of 2008, but 2009 is less than five months away. Another matter may be that the firm merely reaffirmed 2009 guidance, rather than raising that shipment target. This stock market thing is largely an expectations game, after all, and disappointment is the risk you run when investing in a sector with such a sunny outlook.

With a two-star ranking, Canadian Solar clearly hasn't captured the hearts and minds of Motley Fool CAPS players. Check out the bear case and make your own call right over here.

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Fool contributor Toby Shute doesn't have a position in any company mentioned, but he's active in CAPS under the name TMFSmashy. The Motley Fool has a sunny disclosure policy.