Hewlett-Packard today reported that for the first quarter of 2011, the company brought in revenue of $32.3 billion. That's an increase of 4 percent from a year ago, but slightly below what Wall Street was hoping to hear.

Wall Street analysts were expecting revenue between $32.75 billion and $33.59 billion, and earnings per share between $1.26 and $1.32. HP's earnings per share this quarter came in at $1.17 (including 19 cents per share in after-tax costs), which is a 26 percent leap from the 93 cents per share earned a year ago.

HP CEO Leo Apotheker released an upbeat statement on the earnings report: "I'm pleased with our EPS and margin expansion during the quarter. Going forward, we have the opportunity to further capitalize on our customers' demands for higher value-added solutions...HP has a powerful portfolio, including exciting, recently announced cloud and connectivity offerings. We are focused on leveraging these strengths to extend our leadership and accelerate growth."

During a conference call with reporters this afternoon, HP executives gave a couple reasons for HP's miss: the company's enterprise business didn't re-sign or land the same number of big enterprise contracts it expected, and the consumer PC market grew slower than previously anticipated.

"We had good growth in commercial sectors and we gained share in the U.S. enterprise sector. However, it was offset by continued softness in the consumer PC market," Apotheker said.

The good news coming from commercial PC sales should continue for several more quarters. Apotheker used a baseball analogy to describe the ongoing commercial PC refresh cycle, saying it's in the "mid-innings." "This market still has some legs to go," he added.

The Personal Systems Group, which makes HP's PCs, didn't fare so well overall. In total, sales dropped 1 percent for the quarter, and while desktop PC sales were up 1 percent, notebook PC sales were down 5 percent.

As a result, HP today revised its full year 2011 revenue forecast slightly downward from between $131.5 billion and $133.5 billion to between $130 billion and $131.5 billion. CFO Cathie Lesjak explained, "We continue to remain cautious about the consumer spending environment, particularly with PCs." The enterprise business, she added, will "grow behind yearly seasonality." In other words, it will be slower than HP anticipated several months ago.

Apotheker has been CEO of HP for one full quarter, and he said he now feels like "an insider."

"I feel we are positioned to lead the IT industry," he told analysts during a conference call. "It's clear we do a lot of things well. It's also clear there are isolated areas we need to improve. I'm committed to making these improvements."

HP shareholders didn't respond favorably. The company's stock was down 9.4 percent to $43.69 in after-hours trading.

This post was updated several times, most recently at 3:00 p.m. PT.