In a recent filing with the SEC, Carl Icahn revealed that he has increased his stake in speech-to-text software maker Nuance Communications (NASDAQ:NUAN) to nearly 11%. He did this after Nuance reported disappointing earnings and deeply disappointing Q3 guidance, and the stock plunged to new levels of cheapness.

But is Nuance stock cheap for a reason? Fool contributor Rich Smith thinks Icahn is making a big mistake in buying into this company -- maybe even as big as his mistake when he bought into Blockbuster. Listen in, and find out why.