Intel (NASDAQ:INTC) announced after the bell yesterday that it expects to book between $8 billion and $8.2 billion in revenue for the first quarter, narrowing its previously reported range of $7.9 billion to $8.5 billion. The revised numbers lower the midpoint of Intel's guidance, from $8.2 billion to $8.1 billion. Investors weren't happy with the news, sending its shares down by almost 2% in morning trading.

According to published reports, Intel CFO Andy Bryant has suggested that rising inventories among PC manufacturers and weaker-than-expected demand in Japan and throughout Asia were responsible for the shortfall. Intel also said its first quarter is seasonally weak.

Should shareholders be worried? Probably not. Even with its revised guidance, Intel will grow revenue 20%, in line with global semiconductor sales. (Intel booked $6.75 billion in revenue during last year's first quarter.) The company also closed 2003 with more than $13 billion in cash and an authorization to buy back more than 400 million of its outstanding shares, which should keep per-stub earnings on the rise.

That's not to say Intel doesn't face difficulties. After I wrote about Intel's unprecedented move to follow rival Advanced Micro Devices (NYSE:AMD) into the market for combination 32-bit/64-bit chips, my inbox was flooded with mail from Intel doomsayers.

The best argument came from a reader who pointed out that Intel is far from dominant in supplying chips for lower-end 64-bit servers, where competition comes from AMD's Opteron chip, Sun Microsystems' (NASDAQ:SUNW) SPARC, and the PowerPC G5 from Apple Computer (NASDAQ:AAPL) and IBM (NYSE:IBM). And then there are the published reports that Intel's Itanium 64-bit chip -- co-created with Hewlett-Packard (NYSE:HPQ) -- has fallen far short of expectations.

Former Fool Tom Jacobs used to say that every investor's portfolio should contain a good mix of "sleep at night" stocks -- large, dominant companies that are likely to offer some modest growth. I used to consider Intel a model "sleeper" stock. Now I'm not so sure.

With competition heating up and now revised guidance, Intel investors may find themselves with a slight case of insomnia.

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Motley Fool contributor Tim Beyers wonders if there's a chip for curing insomnia. He could have used it last night. Tim has no stake in any companies mentioned here.