Comcast (CMCSA) posted a decline in first-quarter earnings but matched Wall Street estimates. The Philadelphia-based cable system operator made $732 million, or 24 cents a share, for the quarter ended March 31, down from the year-ago $837 million, or 26 cents a share. On an adjusted basis, excluding certain unusual items, earnings rose to 19 cents a share from 17 cents a year ago. Revenue rose 14% from a year earlier to $8.4 billion, beating the $8.2 billion analyst estimate.

“Our performance demonstrates that our operating strategy is working in an economic and competitive environment that continues to be challenging,” said CEO Brian Roberts. Comcast lost 57,000 basic video subscribers, but added 494,000 digital cable subscribers. The company said 65% of video subscribers now have digital service, up from 55% a year ago, and 43% have so-called advanced services like digital video recorders or high-definition TV, up from 38% last year. The company also added 492,000 high-speed Internet users and 639,000 Comcast Digital Voice phone customers.

Comcast, which recently began paying a quarterly dividend for the first time in more than a decade, said it spent $1 billion buying back stock in the quarter. Comcast made $3 billion in repurchases last year as its shares fell, but this year the buybacks seem to have had the desired effect, as Comcast shares rose 6% during the first quarter.

What does Michael Dell have to do to get his company’s stock rising again? On Tuesday morning, Dell (DELL) joined the tech buyback crowd, saying it will repurchase $10 billion worth of its stock in coming months. In doing so, the PC maker joined Cisco (CSCO) and Hewlett-Packard (HPQ) in feeding stacks of greenbacks into the market for the purpose of shoring up the stock price. Yet Dell shares dropped Tuesday, putting the stock below the level it held back in January before Michael Dell came out of retirement to retake the CEO post.

Shareholders like buybacks because they create demand for stocks that wouldn’t necessarily find a lot of willing buyers otherwise. Such is the case with Dell, which generates plenty of cash but shows few signs of any sustainable growth that might appeal to investors. Dell’s comments earlier Tuesday, in service of updating shareholders on strategic priorities, made clear how little the company has to offer right now.

“We are at the dawn of the connected era and Dell has never been better positioned to meet the needs of the billions of people who will join us online in the coming years,” Dell said in the company’s press release. “By establishing clear priorities for growth in consumer, emerging countries, notebooks, small and medium business and the enterprise, we will deliver the products and solutions customers need to simply connect, communicate and collaborate.”

As Fortune’s Adam Lashinsky pointed out last week, the time to buy Dell will be when the doubletalk ends.

Phillips-Van Heusen (PVH) got the starch knocked out of it Tuesday after the shirtmaker’s 2008 profit forecast fell short of Wall Street’s expectations. The company, which makes clothes under the Calvin Klein, Izod and Timberland labels, said it expects to face difficult economic conditions well into next year. That means earnings for the first half of 2008 will be flat with 2007 levels — not the kind of trend investors like to see. The selloff, which took shares down 10% to a 52-week low at $38 and change, came in spite of CEO Emanuel Chirico’s promise to spend $200 million buying back stock. But as Fortune’s Suzanne Kapner recently pointed out, sometimes those sorts of efforts can amount to throwing good money after bad.