The problem was that, even though the line was being drawn around the ring, DataGraph was treating the last label like it was the end of the line, resulting in the offset. We will fix this in the next Beta, and soon to be out 5.0.
For now, here is a hack… Go the column where you have the labels entered. In the row below the last label, double click and simply enter a blank space with the space bar.
The the row with the space is treated like the end of the line and the last text entry, in this case, ’13’, is correctly located.
Not sure if this will fix the second example but we think so. The fix will be out soon so you won’t have to do this hack going forward.