Touch screen - GetPosition not working

I am using t35 touch screen. When i use GetPosition passing display.WPFWindow, i am getting wierd values. When i touch the left toop corner, i expect to get x=2,y=2 or something like that. Instead till some point, i am only getting x=0,y=0. Am i missing something?

Calibration problems perhaps?

do i have to calibrate the touch screen. how? also should it be done evertime the system is powered up?

Make sure you read this as well:

i went through the link and did the test. when i touched the screen where i would expect x=9 or 10 and y=9 or 10, i got x=0,y=0. Not sure why that is. I am under the impression that when i touch the left top corner of the screen, that would be (0,0). The value increases as a i move right or down but the (0,0) seems to be not in the right position. Is this the way it has to be?

0,0 for 9,9 is pretty close. You can sit there and calibrate over and over til you get it exactly how you like but in the end that ought really be close enough.

Got it. I am ok with this. Just wanted to check if i am doing something wrong. Thanks.