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 Rovi Corporation (NASDAQ:ROVI) fell nearly 12% Tuesday after a U.S. Court of Appeals ruled Amazon.com did not infringe two of company's video patents. 

So what: The case began three years ago, when Rovi sued Amazon over two patents related to electronic program guides.

After expressing disappointment and noting the decision involved only two of Rovi's more than 5,000 issued patents and applications, Rovi executive VP Samir Armaly insisted: "We believe that our portfolio is even more relevant to Amazon today and going forward than when the present litigation began in early 2011. Since that time, Amazon has continued to expand its video and over-the-top offerings through new products like the recently announced Fire TV."

Armaly then pointed to Rovi's various recent agreements with other companies as evidence of its patent strength, and promised they "plan to continue to pursue Amazon going forward to take the necessary licenses under our patent portfolio."

Now what: The predominant concern here is that this case could set precedent for other companies that don't wish to pay to license Rovi's technology. While obviously not ideal, however, investors shouldn't be too disheartened as these kinds of setbacks are par for the course for intellectual-property companies like Rovi. Still, this does demonstrate the difficulty Rovi can face in actually cashing in with unwilling prospective licensees.

In the end, and even with shares trading at a seemingly reasonable 11 times next year's estimated earnings, that's why I'm not particularly anxious to buy shares of Rovi today.

Steve Symington owns shares of Apple. The Motley Fool recommends and owns shares of Amazon.com and Apple. Try any of our Foolish newsletter services free for 30 days. We Fools don't all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.