For a company that has achieved so much, Apple sure is a gloomy Gus when it comes to its forecasts.

The maker of iPhones and Macs had stellar revenues this quarter: Rising 43 percent to $7.5 billion, well above Wall Street's forecast of $6.96 billion. Its earnings per share of $1.16 handily beat the Street's number of $1.07.

This was in a quarter when the mania for iPods had calmed and many consumers were waiting for a new version of the iPhone. Yet iPod revenue rose 8 percent on year to $1.8 billion, and the $378,000 in iPhone revenue was better even than the fourth quarter of last year, which included holiday sales.

But what really shone in Apple's report were its Mac computers. Revenue from desktops grew 48 percent to $1.4 billion, and those from Macbook laptops surged 58 percent to $2.1 billion in a quarter when consumers were expected to cut back on spending.

So the current quarter should be just as good, right? Well actually, to hear Apple put it, not really. Revenue will grow only 33 percent and net profit will be $1 a share, smaller than what the company earned last quarter.

This dismal song-and-dance is typical for Apple. It gives conservative estimates, setting the bar low enough to trot over it without working up a sweat.

But it can cause confusion and uncertainty as the market second guesses the company. In aftermarket trading, Apple's stock rose 4 percent above the official closing price of $162.89 as investors saw the strong first-quarter results. Then it fell to 4 percent below the closing price as they took in the cautious second-quarter guidance.

Analysts tried to wring more data from Apple C.F.O. Peter Oppenheimer on the conference call with little result beyond some prickly responses. When one asked a question common on earnings calls these days—any thoughts on the overall economy?—Apple executives sniffed that they're not in the business of economic commentary.

So investors are left with scant clues to crack the koan of Apple's guidance. In good times, they simply assume Apple is aiming very low. But in lean times like 2008, some wonder if conservative guidance has become more middle of the road, if not liberal.

Such uncertainty helped drive Apple's stock down from $200 in early January to $115 in February. It also led analysts Wednesday to zero in on Apple's gross margins, which came in at 32.9 percent.

That figure was in fact 90 basis points—nine-tenths of a percentage point—better than Apple had guided. But Apple usually beats its guidance by a much wider margin: A year ago, Apple's gross margin was 360 basis points better than it had forecast.

Apple has aimed so low that analysts actually worry when it comes close to its projections.

"Apple had really strong revenues, but it didn't quite translate into margins like it historically has," said Shaw Wu, an analyst at American Technology Research. "It looks like this time the guidance on their margins maybe wasn't so conservative."

Oppenheimer said that while falling costs for hard drives, memory chips and displays were helping margins, other factors weighed them down: reduced prices for the iPod shuffle, lower overseas pricing, currency rates, and more sales through iTunes—a relatively low-margin business.

Apple consumers might find such concern to be splitting hairs. They still love their Macs. They love the iPhones so much that they are depleting the inventory at Apple's stores to ship them to countries where the iPhone hasn't launched yet. That's not a bad problem for Apple to have.

Consumers may be cutting back on expenses this year. But conservative guidance or not, there still aren't any hard signs yet that they will abandon Apple.