This thread got me to thinking (always a good thing!) Whenever I cut on my granite kitchen counter top I get good, clean cuts but when I cut on my cutting table I always seem to have problems.
So I got out a big level and did some investigating - sure enough, my cutting table top is not completely level; there is a dip in the middle. I am pondering what to do about it but it is nice to know that for once it was not me that was the problem.