Although we don't believe in timing the market or panicking over market movements, we do like to keep an eye on big changes -- just in case they're material to our investing thesis.

What: Shares of ATM and voting machine maker Diebold (NYSE:DBD) fell as much as 12% today after the company reported preliminary results and cut its full-year forecast.

So what: The company said that it expects third-quarter revenue to be $710 million and earnings per share to be $0.39. Analysts expected $735 million in revenue and earnings of $0.50 per share.

For the full year, management expects growth of 6%, at the low end of the previous range. Earnings per share are expected to be between $2.25 and $2.30, below previous estimates of $2.50 and $2.60.

Now what: A delay in purchases from Brazil is the cause of the weak numbers as well as reduced spending from regional banks in the U.S. A reduction in guidance is never good but we need to keep in mind that revenue is still growing and management said that orders were delayed, not canceled. The stock is trading at just 10 times trailing earnings and pays a 3.4% dividend yield, so I think this is a buying opportunity for Foolish investors with a long-term horizon.

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