Synaptic touchpad: no cursor movement possible with finger on button

I just installed Mint 15 with KDE on my new Samsung Series 7. The touchpad on it is an integrated one; there are no separate buttons, but you can still click it by pressing bottom left and bottom right. This means the buttons themselves can be used as track area.

A consequence of this is, that you can't move your cursor when your finger is resting on the button, because it then registers multi-touch. The expected behavior is that I can rest one finger on a button, and still move the cursor without triggering scroll actions. The reason that is expected, is because:

* This is how it works in Windows
* This is how it works on a Macbook Pro, also with a touchpad without separate buttons.
* You *can* move the pointer while pressing the button.

xserver-xorg-input-synaptics: 1.6.2
Linux Mint 15 Olivia KDE