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 oilfield services specialist Weatherford International (NYSE: WFT) sank 11% in intraday trading Wednesday after the company said it would have to restate its financial statements and delay the filing of its 2010 10-K as a result of accounting issues.

So what: Because of a material weakness in tax reporting that CFO Andrew Becnel labeled an "embarrassment," Weatherford said it would need to adjust the results for the past four years by $500 million. While inadequate tax staffing, ineffective review practices, and weak controls were all blamed for the errors, management made it clear that the problem won't affect Weatherford's previously reported cash flows and debt covenants.

Now what: I'd remain cautious about jumping into the stock. With management expected to revise its previous guidance of a 20% tax rate, the company's future results could be negatively affected as well. When you couple that accounting uncertainty with the political unrest in the Middle East and North Africa that has been disrupting Weatherford's operations, it's clear that there are probably less stressful situations for your investment dollars.

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