I am using LO 4.0.3.3 in Linux Mint 15, Cinnamon 1.8, 32 bit. Nvidia 9600GT - Propriety Driver 310.
In LO Writer with Hardware Acceleration selected on or off, Smooth Scrolling has no effect. I have some very long docs to read and being able to scroll smoothly makes life less tiresome, autoscroll would be nice too, but in this question I am asking why Smooth Scroll has no affect (on my system) - even after a reboot.
I get the same here under Crunchbang 11 (Openbox) on a i7 laptop (small screen) so I doubt it is your hardware or drivers. From memory, I thought this worked OK in the late v3.5 series. This thread would appear to be the same issue only for the Mac platform. Hmmm. There do not appear to be any open bugs about this at present, so we may need to raise a bug. I think others should chime in with their reports first though.
I have the same issue on Kubuntu 13.10, LO 4.1.3.2, AMD Catalyst 13.11 beta. Someone ought to report a bug.