eGalax touchscreen calibration

[ph87]

After spending some loooong nights I got it working!!! I had succesfull calibrated the Touchscreen using your install.sh but...

Today I wanted to test it, but it doesn't work anymore... The Calibration Data have changed! How can the calib data change from one day to another?

data Yesterday: calib_x_d=1220;calib_x_fact=-0.8;calib_y_d=710;calib_y_fact=-0.8;swap_axes=0;
data Today: calib_x_d=1180;calib_x_fact=-0.12;calib_y_d=740;calib_y_fact=-0.1;swap_axes=0;

What does it depend on?

An other problem is, that I've got a 1280x720 screen but ts_calibtrate recognizes it as a 1440x900 so I can't use his data - I've to calibrate it for my own!!!

Hope you can help me...