I hate to beat a dead horse here, but I've been working on some heavily commented code lately and it has been reinforcing my stereotype against code comments.
It led me to come up with this thought (I'm sure it's not original, and if someone else has said it before, let me know and I'll link to it, thx -ed):
As code maintainability decreases, the number and proximity of associated code comments increases
This wouldn't be so bad -- sometimes, bad code happens (I really need to make a T-shirt of this) -- except that the comments were (usually) written at the same time as the code. This means that the coder committed a pre-meditated crime against a would-be maintenance programmer (usually, him/herself)! By the way, I use the word 'crime' in a more poetic/allegorical sense.
If you KNOW it's bad/overly-complex and requires a comment, why not just do it right in the first place?