I upgraded from 10.04 to 10.10 because i could not get my touchscreen to calibrate correctly, although I tried using the xinput_calibrator tool. In 10.04 i was able to get the touchscreen to react to a touch (although badly calibrated) by installing multitouch-kernel-source (bytetips.com/touchscreen-support-ubuntu) but there was no calibrator tool installed by default.
I upgraded to 10.10 and now there is a built-in calibrator (which I used several times with no effect), but the touchscreen is not working (ie, cursor shows no reaction to touching screen). There is a terminal window that never closes (without me manually closing it) which says:
Warning: multiple calibratable devices found, calibrating last one (Quanta Computer Inc. Optical Touch Screen) use --device to select another one. Calibrating standard Xorg driver "Quanta Computer Inc. Optical Touch Screen" current calibration values: min_x=0, max_x=1023 and min_y=0, max_y=767 If these values are estimated wrong, either supply it manually with the --precalib option, or run the 'get_precalib.sh' script to automatically get it (through HAL).