Erratic behavior of tapping

Binary package hint: xserver-xorg-input-synaptics

When I click with the separate button (no tapping), usually only the button pressing event is sent. The release event is only sent when I move the cursor.
Sometimes I try to simply move the cursor and the touchpad enables click-and-drag just as if I did a double-tap-and-move, but without doing the double-tapping. This looks related to a problem in which I single-tap, then when I move the cursor it starts dragging... looks like the driver is not respecting the MaxTapTime and MaxTapMove values.
If I use tapping with two or three fingers, then the above symptom is done with middle-button-drag and right-button-drag.
Some times the single-click tap does not work.

I have fixed the problem in two ways:
1) Disable the synaptics driver commenting the touchpad entry in xorg.conf. This is not the best option, as I lose the touchpad features such as scrolling and double-tapping, etc.
2) I downloaded an updated package from packages.debian.org (testing branch) and installed it. Now everything is working flawlessly.