Apple will announce its latest financial earnings today. And Piper Jaffray analyst Gene Munster thinks the results may disappoint investors.

Why? “Silicon Alley Insider (http://www.businessinsider.com/apple-earnings-2010-10?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+typepad%2Falleyinsider%2Fsilicon_alley_insider+%28Silicon+Alley+Insider%29) says the analyst told clients that the iPad has a lower profit margin than investors think. Also, supply-constraints have prevented Apple from selling as many iPads as it could have.

“Don’t expect typical EPS upside due to iPad,” Munster says. “The Street is looking for EPS of $4.05. Assuming a typical beat over the past 17 quarters, Apple would report $4.80.”