The problem is related to electrical interference from the power supply (see http://superuser.com/questions/76649/laptop-touchpad-works- incorrectly-when-on-power-supply). As suggested by users here, increasing the noise threshold helps.
In my case, this problem happens because I am using a cheap ebay power supply that was not manufactured by my laptop's maker. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1028617 Title: Cursor shakes violently when connected to power source - makes touchpad cursor unusable To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/xserver-xorg-input-synaptics/+bug/1028617/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
