Inking is out of line with the pen
When signing on a DTU (or other Wacom device which extends the Windows desktop) the ink is not in line with the pen
If the inking is only a few millimetres away from the point of the pen then you probably need to calibrate your Wacom device via the Wacom Tablet Properties control panel.
If the inking is significantly further away, maybe even off the signature capture window, then the normal remedy is to remove user preferences.
This is done via the Wacom Desktop Center which you can find by searching via your Start menu.
When it appears click on Backup settings on the left, and then "Reset settings" (ringed in red below) and wait till it finishes.
If neither of the above works please see also the Pen Gap FAQ