I cannot really help but I have some suggestions.
First, are you sure you are using the synaptics driver, and not evdev? Check in the X log file /var/log/Xorg.0.log
You can access synaptics options using synclient. Could you report your current configuration?
Then, try to change the sensitivity values. For instance, on my laptop I have "FingerHigh = 30"
If I change the value to 50 with
the tapping is less sensitive. (For the options, look at 'man synaptics').
Well, this is all I can tell...