Hi,
you reported a problem with the synaptics driver not reporting any
events for your touchpad.
Can you attach the contents of /proc/bus/input/devices to this bug?
Also, please test with the packages from testing (you would need to
downgrade your video driver, input drivers and xserver-xorg-core), and
if that works please attach the Xorg log.
The information so far in this bug only shows that a previous version of
synaptics couldn't load with xserver 1.4 due to unresolved symbols,
but nothing showing the driver works on your systems, unless I've missed
something.