I tried to calibrate my surface to suit my writing style but it is impossible to hit the extreme corners of the calibration tool (specifically the lower. left corner if viewed with Windows button on the bottom). This makes it impossible to calibrate properly. The default works alright but isn't perfect. I've also noticed that as the pen approaches the edge of the screen there is a "jump" of the pointer like it's being sucked to the edge of the screen. Has anyone else noticed this or do I have a dud Wacom digitizer?
You might try:
Reset any existing calibration in Tablet PC settings.
Press Win key, type "Run"
Copy and paste the following into the Run window:
tabcal lincal novalidate XGridPts=10,60,110,360,660,960,1260,1560,1860,1910 YGridPts=10,60,170,330,490,650,810,970,1020,1070
Run the command, allow permissions, go through the calibration. This makes for near perfect pen accuracy, but it's never going to be perfect. Corners will still be messed up, but that's how it works, apparently. More X and Y points can be added to the lists for even more precision. Each number just corresponds to the X or Y coordinate of a pixel on the screen.
Source:
Improved Pen Accuracy with a 100 Point Calibration Grid : Surface