OK, this might be a bug, it might be my own model being wonky, so I'll try and be as detailed as I can.

Lenovo X61 Tablet (7764-CTO)
Jaunty 9.04 amd64
Used Tom's deb from Method #3

4 out of 5 times, everything works fine! That 5th time, however, calibration is suddenly lost after rotating. When this happens, half the time the tablet thinks it's still in Landscape mode, the other half it goes to portrait but my input is about an inch off.

Opening wacomcpl and recalibrating fixes everything, and it holds its calibration through rotations for the next 4 out of 5 times.

Just seems to be a random glitch.