I like to setup tapbutton3=8, so triple tap is browser back. This is troublesome on a lot of Ubuntu-based distros unfortunately.
I have setup a 50-synaptics.conf with the proper options, and synclient reports tapbutton3=8, but actually functionality is always tapbutton3=1 (left click). I experimented with tapbutton2=8 and this does work, setting double tap to browser back. So it seems that for some reason tapbutton3 is not changing from being left click even though syncient reports that it is.
This is my EeePC 900 running Mint 12 LXDE fully distro-updated.