Bed levelling issue

Here is one that will surely trip you up if you're trying to be clever: I changed the maximum limits in the Marlin code to 15 minimum and 185 maximum in both X and Y axes. The reason is that my bed is exactly 200 x 200, and running a calibration procedure pretty much always puts the J-head off the glass at at least one corner. By changing the edges to 15mm in on all sides, the levelling calibration procedure (M371, M372 and M373) stays on the glass, making calibration easy. Only, the table that gets generated seems to be off. I changed back to 0 and 200 and it LOOKS better (moving to X100 Y100 Z0 is spot on). Printing now to see how the first layer will look.