Technology giant Hewlett-Packard (NYSE:HPQ) reported a robust third quarter yesterday, and Wall Street loved it. The stock is leading the New York Stock Exchange's most actives list and is one of the top five percentage gainers for the day.

Third-quarter revenue, compared with the comparable quarter last year, rose 10%. Net income soared 46% if you ignore a one-time $988 million "tax adjustment" to repatriate $14.5 billion in cash from foreign earnings.

But digging deep into the quarter's numbers does not explain Wall Street's buying stampede. A year ago, then-CEO Carly Fiorina was bemoaning the "unacceptable execution in Enterprise Storage and Servers," which had lost the company $211 million. This quarter's $150 million profit in the same unit (a $361 million swing) accounts for 86.6% of the total company improvement in operating profits.

While going from a loss to a profit is always good -- always! -- remember that a year ago there was an immediate management change and the company accelerated the margin improvement plan for this business. Tell me: Though it represents progress, is a 3.8% operating margin that great?

The other group where profits came to life was Personal Systems. This unit, which includes personal computers, saw its operating profits increase almost sixfold to $163 million. Here too, though, the operating margin left something to be desired at just 2.6%.

The news wasn't as good for Imaging and Printing, HP's core profit contributor. Although revenue increased 5% year over year in this sector, operating profits fell $65 million (7.8%). Still, this division's 13% operating margin (down 1.8% points from last year) marks the highest among the company's four operating groups.

It is no secret that HP has to work on its operating margins. The good news is that overall, they increased from 4.5% in the year-ago quarter to 5.7% this quarter. But when compared with the trailing annual operating margins at its competitors, including Motley Fool Stock Advisor recommendation Dell (NASDAQ:DELL), IBM (NYSE:IBM), Canon (NYSE:CAJ), and Apple (NASDAQ:AAPL) -- 8.7%, 12.4%, 15.7%, and 10.8%, respectively -- HP's numbers still look weak.

The company expects to earn between $0.44 and $0.47 a share next quarter. That exceeds the $0.43 that analysts are expecting, and that alone may account for today's stampede. It also may not hurt that new printer technology could give the Printing and Imaging division a competitive advantage to start growing profits and margins again.

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Fool contributor W.D. Crotty does not own shares in any of the companies mentioned. Click here to see The Motley Fool's disclosure policy.