I sent this prototype drawing out for machining (cleaned for easier viewing), and I got a call from the Machine Shop asking if the .630 dimension was correct. I checked and said NO, the dimension is .421! I thought I accidentally overrode the .630 dimension (as a rule, I rarely if ever override dimensions). So I opened the drawing again and added a Smart Dimension to the same hole from the top of the part, and every time I get .630. If I use Vertical Dimension, I get .421. So, after investigating, the .630 distance is the center of the small hole on the front surface to the center of the top of the cylindrical feature (.125 feature), which is out of plane for this drawing view. Anyone see Smart Dimension give such an error? There was no warning this dimension would out of plane, so I wonder if this has every happened before.