Comment 33 for bug 1506817

Here is a summary of the two commands from comment #32 (above) for the X250.

1) The driver is different between the X201 and the X250
1.8.2-1ubuntu1 <-- X201 (Working)
1.8.2-1ubuntu3 <-- X250 (Not working)

2) For the X201 the apt-cache results different (none installed), while for the X250 the driver is installed.
    Installed: (none)
    Candidate: 1.8.2-1ubuntu1 <--- X201

  Installed: 1.8.2-1ubuntu3
  Candidate: 1.8.2-1ubuntu3 <--- X250

apt-cache policy xserver-xorg-input-synaptics
xserver-xorg-input-synaptics:
  Installed: 1.8.2-1ubuntu3
  Candidate: 1.8.2-1ubuntu3
  Version table:
 *** 1.8.2-1ubuntu3 500 1.8.
        500 http://us.archive.ubuntu.com/ubuntu xenial/main amd64 Packages
        100 /var/lib/dpkg/status

 dpkg -l | grep synaptics
ii xserver-xorg-input-synaptics 1.8.2-1ubuntu3 amd64 Synaptics TouchPad driver for X.Org server