Cheers for the pointer, cyberdork. I'd read about this elsewhere, but I'm not looking to engage Multitouch features just yet, simply being able to use the trackpad would be a start. Booting into the 8.04 LiveCD, for example, renders the trackpad workable, however I literally get no response from it when running my Ubuntu installtion.
I had a look in my Xorg.0.log and confirmed what I thought might be happening: the Synaptics driver is refusing to load for whatever reason. Here are the relevant lines:
I'm going to try uninstalling and then reinstalling the driver and see if that helps.
(II) Synaptics touchpad driver version 0.14.6 (1406)
Synaptics Touchpad no synaptics event device found (checked 22 nodes)
(**) Option "Device" "/dev/psaux"
(**) Option "HorizEdgeScroll" "0"
Query no Synaptics: 6003C8
(EE) Synaptics Touchpad no synaptics touchpad detected and no repeater device
(EE) Synaptics Touchpad Unable to query/initialize Synaptics hardware.
(EE) PreInit failed for input device "Synaptics Touchpad"
(II) UnloadModule: "synaptics"
EDIT: Reinstalling xorg synaptics driver didn't do anything. Any other suggestions for what I could try?