Hi, there are bugs with float properties handling on 64bit in both synclient and xinput. They're fixed upstream, so you could try to see if that fixes your issues. synaptics is at git://anongit.freedesktop.org/xorg/driver/xf86-input-synaptics and xinput at git://anongit.freedesktop.org/xorg/app/xinput. Cheers, Julien