It happens to every company sooner or later: Wall Street sets a mark for quarterly earnings, and the company misses that goal. Sometimes an earnings stumble is a signal to sell, but digging in the dirt is also a good way to find turnaround candidates while they're getting beaten down. Today, we'll see that video-on-demand still needs some tuning, even Plato has a lot left to learn, and all is not as it seems in Chicago.

Our first underperformer today is SeaChangeInternational (NASDAQ:SEAC). The maker of infrastructure equipment and software for video-on-demand operations reported a $4.4 million net loss this quarter, or $0.15 per diluted share. That's 87% worse than the expected $0.08 loss per share, but the market still saw the report as a net positive. Investors rewarded the company with a 15% higher share price overnight.

Why? To begin with, the on-demand video business is still in its infancy. Management comments in the earnings release pointed to strong prospects, as several large, multiyear customer agreement negotiations are under way. Could SeaChange be talking to Amazon.com (NASDAQ:AMZN), or Netflix (NASDAQ:NFLX), or maybe directly to the large content producers? Future press releases are sure to tell that story, but I think it doesn't matter very much. If video-on-demand becomes what I think it will be, SeaChange will have more new business on its hands than it can manage, and there's room for several players in this market.

PLATO Learning (NASDAQ:TUTR) is our second straggler this week. The online learning systems provider reported a net loss of $0.25 per share. That's almost twice the red ink of last year's $0.13 for the comparable quarter, and way lower than the negative $0.02 per share forecast by analysts.

Revenues came in at $20 million, 36% below the $31.5 million seen last year, so it's not hard to see why losses were magnified. According to management, the company is in the middle of transitioning to a new product line, new subscription-based licensing programs, and new customer segments, and a freshly hired set of sales account managers are still learning the ropes of the business.

It's a little bit ironic to see a training and education company blame the learning curve of new processes for their problems, but that's what PLATO is doing here. The company thinks that it's a temporary situation, and that sales and income will inch back up once all the new procedures have been absorbed. I'd give PLATO a hall pass for a couple of quarters and check back on its progress toward the end of the year. If it's still cramming by then, I'm afraid the test was too hard.

Chicago Bridge & Iron (NYSE:CBI) is based in Hoofddorp, the Netherlands, builds more oil and gas processing equipment than it builds bridges, and is not in the ironworking business. The engineering firm was expected to bring in $0.19 of earnings per diluted share this quarter, but it managed only $0.13. That's 32% below the target and 19% below the comparable quarter of 2005, despite 35% higher revenue year over year.

The difference is explained by more expensive projects, which brought gross margins down from 10.6% to 9.2% year over year, and much higher sales, general, and administrative expenses. Say hello to our old friend "the stock options expense" again. The company didn't break out SFAS 123 expenses separately, but it did say that the charges accounted for the majority of the operational expense increase, alongside corporate restructuring and internal accounting inquiry charges.

An audit flagged two contracts for possible inappropriate accounting practices last year, which led to the loss of the company's CFO, COO, and CEO in a two-month span. The company believes these problems have been corrected, and given its $3.4 billion order backlog, its future is looking brighter. Chicago Bridge & Iron should be able to leave the sordid accounting affair behind and refocus its efforts on the lucrative oil infrastructure business.

Some of these underperformers are victims of larger circumstances, while others might have only themselves to blame. It's up to you to decide which down-on-their-luck companies should be able to pull themselves up by the bootstraps and which really are stuck in the mud. Come back next Monday, and we'll take a look at another batch of mishaps and disappointments. It'll be fun and educational. Promise.

Further Foolishness that won't disappoint:

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Netflix and Amazon.com both made Tom and David Gardner's list at Motley Fool Stock Advisor.

Fool contributor Anders Bylund owns shares in Netflix but holds no position in the other companies discussed this week. He can smell the sea change on the entertainment breeze. Unlike these companies, Foolish disclosure is always reliable.