Myth No. 5: "You should never close an account if you can help it."

Fact: The prevailing myth used to be that closing accounts could help your scores, which, we've learned, isn't true. But the knowledge that shutting accounts can hurt your scores has caused some people to balk at closing credit accounts, even when they probably should.

If your issuer is charging you a fee you don't want to pay, for example, closing a card or two shouldn't be a crisis if you have good scores, other open accounts and no plans to apply for credit in the immediate future. If you do plan to apply for a mortgage, car loan or new credit card, though, you should hold off on closing any accounts until after you've been approved.

Myth No. 6: "How you handle credit indicates how trustworthy you are."

Fact: People get in financial trouble for all kinds of reasons, including simply getting sick (medical bills were a factor in nearly two-thirds of consumer bankruptcies in 2007, according to Harvard University researchers).

There's no evidence of a link between information on credit reports and the likelihood an employee will commit fraud, but employers persist in thinking there is. (By the way, employers typically use credit reports to evaluate applicants, not credit scores.)

Furthermore, there is evidence that employers are abusing their power to review credit reports Some states have already banned or limited pre-employment credit checks, and a bill was introduced in 2009-2010 session of Congress to do the same, although the legislation didn't go anywhere.

Myth No. 7: "All credit scores are pretty much the same."

Fact: There are hundreds of different credit scoring formulas. Even the scoring formula used by most lenders, the FICO, comes in different iterations. One lender may use the most up-to-date formula while another might use an older version that gives a different result. There are FICOs tweaked to accommodate car lenders, credit card lenders and finance companies, in addition to the "classic" FICO used by most mortgage lenders.

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Some purveyors of other scoring formulas point to these different versions to try to convince people that it doesn't matter which score you get, since there are so many variations. Indeed, if you're simply looking for a guidepost as you try to shore up your finances, any of them can give you an idea of your credit's relative strength.

But if there's real money at stake, you want to get a score that's at least in the same ballpark as the one your lender will be using, and that's typically a FICO. If you're buying a credit score that doesn't say it's a FICO, it's not a FICO -- and it could be dozens or even hundreds of points different from the one your lender sees.

Liz Weston is the Web's most-read personal-finance writer. She is the author of several books, most recently "The 10 Commandments of Money: Survive and Thrive in the New Economy" (find it on Bing). Weston's award-winning columns appear every Monday and Thursday, exclusively on MSN Money. Join the conversation and send in your financial questions on Liz Weston's Facebook fan page.