Touchpad trouble with two- and three-finger touch

[Stefanos A.]

Hello,

I am having trouble registering multi-finger touches using libinput.
Roughly 50% of the time a touch will fail to register. Once a touch
registers, then the next several touches also register. If it fails
then there's again a roughly 50% chance of the next one registering.

The distance or configuration of the fingers on the touchpad do not
appear to matter.

This is on Arch, using Gnome 3.16.0 and libinput 0.13.0. Hardware is a
Samsung RC520 (15.6inch) laptop and `cat /proc/bus/input/devices`
gives me the following touchpad:

I: Bus=0011 Vendor=0002 Product=0007 Version=01b1
N: Name="SynPS/2 Synaptics TouchPad"
P: Phys=isa0060/serio1/input0
S: Sysfs=/devices/platform/i8042/serio1/input/input9
U: Uniq=
H: Handlers=event12 mouse0
B: PROP=9
B: EV=b
B: KEY=6420 30000 0 0 0 0
B: ABS=260800011000003

Any ideas on how to proceed?