Forgive me, but I'm new at Linux.
I was having trouble getting my touchpad to scroll on my HP DV4230 w/Alps pad. I tried all the solutions posted. What finally worked, I renamed etc/x11/50-synaptics.conf to x50-synaptics.conf which I assume means no config file. On re-boot everything including the scroll worked, but it was slow,one or two lines at a time.
Then using both Synaptiks and GSynaptics I finally got the scroll speed working between using both apps. One would do what the other won't. The coasting function isn't working, but that's not a big deal for me.
Why this worked I don't have a clue, but I thought I'd pass the info on so someone with more knowledge than I can figure it out!