Recent weeks have brought media industry watchers no shortage of trade-publication headlines about the strength of the early-year recovery in the advertising market. Investors, however, have been wary.

They've been slow to jump aboard newspaper stocks this year, as evidenced by a six-month chart that shows New York Times (NYSE:NYT), Gannett (NYSE:GCI), Tribune (NYSE:TRB), and Knight Ridder (NYSE:KRI) all underperforming the S&P 500 during that period.

Earlier this month, the market decided it didn't like the news from Tribune. Revenue was up, but not as much as hoped, and the company is now talking cuts. Yesterday, the market was talking about the Times. It said after Tuesday's close that year-to-date revenues were up less than 3%. "The advertising marketplace is still not as robust or predictable as we would like to see in a reviving economy," said Times CFO Leonard Forman in a press release. Knight Ridder's May numbers looked similar to the others; its midyear report comes out on June 22. So does Gannett's.

Investors following the newspaper biz clearly have to take the projections of an ad recovery with a grain of salt -- and maybe a whole salt lick. (This would likely carry over to the magazine business, too, though new rags are still coming out and some market watchers are gushing over the resilience and resurgence of some Silicon Valley publications.) While there's optimism in them thar industry projections, they come with some very real signs that things aren't going as well for many papers as publishers and investors would like.

And it doesn't take in-depth investigative reporting to find the rough spots. At Dow Jones (NYSE:DJ), unionized reporters were forgoing bylines to indicate their displeasure with the state of labor talks with TheWall Street Journal parent. Layoffs are being discussed at the Pulitzer powerhouse Los Angeles Times, while a buyout plan at Baltimore's The Sun has employees fearing pink slips. The Chicago Sun-Times, meanwhile, has been outed for systematically inflating circulation numbers.

In short, there's more to the state of the newspaper biz than rosy ad projections. It's not enough for investors to read about it: To stay informed, to borrow a cliche, they'll have to read all about it.

Fool contributor Dave Marino-Nachison doesn't own any of the companies in this story.