Bad days. We all have them; some of us deserve them.

Here are five stocks whose naughty ways drew investors' scorn on Wednesday:

Company

Closing Price

CAPS Rating (out of 5)

% Change

52-Week Range

Veraz Networks (Nasdaq: VRAZ)

$3.23

***

(34.08%)

$3.04-$8.33

NutriSystem (Nasdaq: NTRI)

$16.58

***

(30.60%)

$16.32-$74.09

3Com (Nasdaq: COMS)

$2.87

**

(23.06%)

$2.84-$5.11

Noah Education (NYSE: NED)

$5.73

***

(15.61%)

$4.81-$23.70

KKR Financial Holdings (NYSE: KFN)

$14.25

*

(1.93%)

$9.39-$30.01

Sources: The Wall Street Journal, Yahoo! Finance, Motley Fool CAPS.

Naughty?
Well, OK, we can't exactly call these stocks naughty. There are days when five-star winners and newsletter recommendations appear here.

But, if you're an investor, you'll have plenty of bad days. The trick is to avoid dating -- or, worse, marrying -- your losers. That's why I listen when our 83,000-plus-person-strong Motley Fool CAPS community of stock pickers speaks with a poor rating or a negative pitch. You should too.

Thus, here is today's list of the worst stocks in the world.

Worse
We begin with NutriSystem, which on Tuesday night projected 2008 revenue that was well below Wall Street's best guess.

And I do mean "well below." The weight-loss company projected $690 million to $710 million in full-year revenue. Analysts, by contrast, were looking for at least $825 million.

Management blamed the broader economy for the shortfall. Quoting CEO Michael Hagan from a company statement: "The environment grew more challenging in January 2008 and we believe the economy is playing a role in consumer discretionary items such as weight loss programs. Given that uncertainty, we believe it's prudent to be cautious with our outlook at this time."

So my gravity-challenged neighbor got suckered into a subprime loan? I'd believe that if NutriSystem peer Weight Watchers (NYSE: WTW) had projected similarly poor results last week. It didn't.

Worser
Next up is KKR Financial, a division of private-equity firm Kohlberg Kravis Roberts & Co. that on Wednesday said it would delay repayment of millions in loans as it seeks to find "a path to a more definitive restructuring that benefits all parties."

Which is to say that KKR has every intention of paying its creditors, but on terms that won't bankrupt the fund.

I can't complain about the basic idea. KKR should negotiate by whatever means it can to avoid default. What troubles me, and why KKR makes our list, is that this is the second time KKR has asked its creditors for leeway.

To me, that's the mark of a business facing more trouble than it's willing to admit.

Worst
But our winner is Noah Education, which provides interactive learning tools in China.

The company materially lowered its full-fiscal year guidance. Noah now expects to book 680 million to 690 million Chinese renminbi (RMB) in revenue, down from an earlier projection of 720 million to 730 million RMB.

Every company experiences hiccups like this from time to time. What makes this one special? Noah didn't specify in its press release that it had revised guidance. It opted instead to gloss over quality problems that led to a slight decline in revenue. Quoting CEO Dong Xu: "Overall this quarter has been a solid one for Noah. Sales of our DLDs [Digital Learning Devices] were down primarily due to the market reaction to a missing environmental compliance sticker on one of our products and our subsequent voluntary action to address customer concerns regarding this issue."

A "solid quarter" built on lower revenue and compliance issues? I don't think so.

Noah Education and its let's-not-say-anything-and-see-whether-they-notice management team ... Wednesday's worst stock in the CAPS world.

Do you agree? Disagree? Let us know what you think by signing up for CAPS today. It's 100% free to participate.

I'll be back tomorrow with more stock horror stories.