It's my understanding that if you set the CD/DVD burner to a slower burn rate, that the burn will be sort of "deeper" into the actual disc medium. Theoretically, this means that if you take a CD burned at a high burn rate and a CD burned at a slow burn rate, and gave them both a light scratch, the CD that was burned slower would less susceptible to skip, than the one that was burned faster.
I don't have any proof or documentation for this though; any comments/corrections are welcome.
Davis