In the download section there are three folders. What they are and what you need:
a. acerhkgui: This folder contains the GUI front end, the driver, and install script all in one package. If the driver installation doesn't work, try one of the other packages.
0.7.2.1 Should work for all Ubuntus
0.7.2 Ubuntu 09.10 - 10.10 (prior to 09.10, acerhk.ko was included.)
b. acerhk_driver_install_script: This folder is a script to install the driver. The first version will download source and compile. The latest version includes source in archive.
c. acerhk_driver_fixed-compile: This foldier contains an edited version of the source that should compile either with the script or, in the case of latest, from commandline process.