From Gamasutra (registration required):

«When I first started writing commercial game code, my code was liberally littered with comments, and I couldn’t imagine any drawbacks to this. As time passed, I noticed something odd: the code and the comments grew increasingly out of sync, and I found that wrong comments cost me more time than correct comments saved me. The cutting and pasting, and late night alterations that happen when the pressure’s on all meant that the code changed while the comments didn’t.»

I couldn’t be more in sync with the sentiments of this article. Copious comments can breed laziness. Debug code! If the code is hard to understand, rewrite it!