I agree - and take it a step further.

Misrepresenting one's skills and/or knowledge does a disservice to everyone involved. I once found myself in a position where the new employer misrepresented my skills to the rest of the organization - essentially set me up for failure with my new co-workers before I ever set foot in the door. Although I was eventually able to do the job, the long-term effect was a lot of bad attitude. Consequently I have a tendency to "undersell" myself ever since.