[mkgmap-dev] Clipping not working correctly?

I'm using splitter to split up a region in 4 tiles. The result has bounding boxes which dont overlap. But if I transfer the resulting img to my etrex, then there the bounding boxes overlap by approx. 0.08 degrees, which is the plus and minus direction of the default overlapping from the splitter. See attached screenshot. So I assume that the clipping of mkgmap doesn't work correctly. I can try with the trunk or with the nod branch, there is no difference. Has anyone else seen the same problem, or am I doing something wrong? My target would be to get the inter-tile routing patch working, which isn't the case at the moment.