Are the tarnished times over for Alcoa (NYSE:AA)? It sure sounded like a shiny fourth quarter for the aluminum producer. The company reported a profit Thursday, a nice improvement compared to the same time last year. However, it seems all that glitters is not gold, as investors dragged the stock down today.

Alcoa's fourth-quarter net income came in at $291 million, or $0.33 a share, with sales of $5.5 billion, a 9% improvement over last year. The company had other good things to say, such as the retirement of $1.2 billion in debt over the course of the year. The company cited higher prices for its products, an improving market for aluminum, and savings from cost-cutting measures.

Last year, Alcoa reported a net loss of $223 million, or $0.26 per share. The subsequent meltdown led to a restructuring that cost 8,000 of its 127,000 employees their jobs. (For a quick flashback, check out Fool LouAnn Lofton's commentary.)

However, while a profit beats a loss in the investor's version of "rock-paper-scissors," analysts and investors questioned some onetime gains that might have made the results look more exciting than they really are -- such as a $105 million gain due to insurance settlements. Fool Jeff Hwang pointed out that similar questions were raised about Alcoa's results from last quarter.

Things may get tougher for Alcoa before they improve. The manufacturing sector recently received some bad news when the Commerce Department announced that November factory orders fell by 1.4% after two months of increases. That doesn't bode well for the stock as investors demand sales growth rather than earnings growth attributable to cost savings and onetime gains.

Did you know that "Alcoa" was originally an acronym? Have your own take on the Q4 numbers? Voice your opinions on our Alcoa discussion board.

Alyce Lomax welcomes your feedback at alomax@fool.com .