Ok, seems that some Ubuntu guys already detected that problem: https://bugs.launchpad.net/ubuntu/+sour ... ug/1067801
That probably describes my issue, because I have the same the same computer mentioned there.
Shortly; Touchpad is misdetected as a PS/2 Mouse on a Fujitsu A512
I didn't undersand very well if that problem was soleved by them or not.
Anyway, if anybody knows what to do if toucpad is wrongly detected, let me know, because that small thing is kinda annoying.