Oh, how quickly things turn. Earlier this month, Gap(NYSE: GPS) reported January same-store sales and also raised its Q4 earnings target, wooing the market. You'd have thought the company hung the moon, listening to the scores of glowing reports issued by analysts.

And then when it actually reports those Q4 earnings and meets targets, its shares fall off more than 10% today on concerns over February comps and margins. Fickle, fickle.

Let's talk about Gap's results first before getting into today's sell-off. It wasn't a horrible quarter or fiscal year for the ubiquitous retailer. But then again, it has an ugly couple of years to rebound from, giving it low hurdles.

Fourth-quarter sales improved 14% to $4.7 billion, and annual sales inched up 4% to $14.5 billion. Same-store sales in Q4 increased 8%, bouncing easily off last year's Q4 drop of 16%. For the entire year, comps were off 3% versus a 13% decline for 2001.

Gap earned $249 million, or $0.27 a diluted share, in Q4. That reverses the prior-period loss of $34 million ($0.04 a share) and matches analysts' expectations. Higher margins, greater cost cutting, and a more favorable effective tax rate boosted its bottom line.

One troubling aspect about its results is the relative weakness of its flagship Gap U.S. stores. Old Navy is again the company's workhorse, with total sales up 27% for the quarter to $1.9 billion and up almost 14% for the year to $5.8 billion.

Stateside Gap stores, however, only saw Q4 sales growth of 6% to $1.6 billion. Total sales for the Gap brand were actually down slightly for the year to $5.1 billion from $5.2 billion. In order to truly fashion a turn-around, the company needs to grow sales again at its flagship stores.

The market's discounting shares today, though, thanks to what Gap said about its February comps and margin trends. Be it because of nasty weather or nervous consumers, comps are, so far, below what Gap had expected for the month. The retailer also said that customers have been reluctant to buy clothes at full price and, as a result, markdowns will pressure margins.

Like shifting fashions, the market's quick to love and then condemn Gap. Patient investors should take a longer-term view.

Foolish Disclosure: LouAnn Lofton owns shares of Gap.