But, it's not what you think.
For a very long time my jointer has been giving me fits because I never seem to get it just right. I've replaced the fence a couple of times and got it close, sometimes, but never "right on". Now I know why. I discovered this while doing some fine tuning earlier today.
Attachment 30047Attachment 30048
This has produced a slight belly in the in-feed table that allows me to read the fence at 90* in one place, but not another. Well, I guess I need to order a part.