Value investing is one of the most successful moneymaking strategies in the market. Master investor Warren Buffett, for example, has earned greater-than-20% annualized returns for the past 40 years by buying good companies when they're cheap.

Unfortunately, companies often get cheap for a reason: Something may be wrong with them.

The ugly
One of Buffett's best investments was taking a major stake in Coca-Cola in the fall of 1988 -- in the aftermath of 1987's Black Monday crash, when most analysts thought Coke's growth prospects looked dim.

Since 1988, Buffett's investment in Coke has earned approximately 16% annualized returns. That's market-beating -- though not as impressive as it once was, if only because Coke has again declined as analysts doubt the brand's power and growth prospects.

Will Coke stay down for the count this time? Motley Fool Inside Value lead analyst Philip Durell doesn't think so. He recommended the company to subscribers in the January 2005 issue, for many of the same reasons Buffett bought in 1988. Coke's situation is just ugly enough to get you a great price on a good company. The same could also be said for the technological questions that dog Intel (NASDAQ:INTC), the lawsuits and patent expirations that threaten Merck (NYSE:MRK) and Pfizer (NYSE:PFE), or the flagging demand and capital crunch that face homebuilders such as MDC Holdings (NYSE:MDC) and Toll Brothers (NYSE:TOL).

Although Coke isn't firing on all cylinders right now, there are no illegalities, and CEO Neville Isdell is focused on spurring future growth. The market will come around.

When ugly is too ugly
But it can get pretty ugly out there. Master small-cap investor David Nierenberg recently told Fool co-founder Tom Gardner that two clear indications can help you steer clear of an ugly situation. First, "If we see an ethical blemish on the part of the incumbent management or the board, we are absolutely not interested. The second is: If we cannot trust or understand their accounting, we are absolutely not interested."

Krispy Kreme Doughnuts is one stock that Nierenberg had been avoiding when Tom interviewed him in 2005. Although new management was trying to turn the business around, the company had not yet released any new, reliable 10-Ks or 10-Qs. (It did so in April 2006.) As Nierenberg wondered to Tom before those releases, "[Has] this company ever earned a real profit? And what return on invested capital has it actually made at the newly opened stores?" Without answers to those questions, it was impossible to determine in 2005 at what price Krispy Kreme was a value -- if any.

The Foolish bottom line
When you're trolling for values in the market, you'll find some ugly situations. Without reliable management and financials, consider the situation too ugly for your dollars.

Separating the ugly from the too ugly can be tricky. If you'd like some help, consider a 30-day free trial to Motley Fool Inside Value. Philip specializes in finding ugly situations ripe for a profitable turnaround -- whether it's because of new management, new strategies, or new events. Click here to learn more.

This article was originally published on Jan. 31, 2006. It has been updated.

Tim Hanson does not own shares of any company mentioned. Coke, Intel, and Pfizer are Inside Value picks. MDC Holdings is a Motley Fool Hidden Gems choice. No Fool is too cool for disclosure.