Your mouse behaviour is controlled by what is in /etc/X11/xorg.conf file. There is a section for each mouse.
Here is what it will look like.
Option "Protocol" "ExplorerPS/2"
Option "Device" "/dev/input/mice"
There should be one section for each mouse. The protocol usually is what you can change to see if that will change behaviour.
There may well be a problem if the hardware is bleeding edge. There are several things I would try.
First of all, install another desktop. You can then pick the other desktop at the login page. I have Xfce installed along with KDE4. There are other choices, Gnome for example. See if the behaviour is the same in another desktop. If it is, then you know in is not KDE4. If the problem goes away, use the other desktop until you find a fix.
I would also install a standard 3 button mouse ( two buttons and a wheel ). They are cheap enough. If that works, then there is another work around.
You can try other configurations through MCC-->Hardware-->Setup a mouse.
Hope this helps.