10.10 - Decrease mouse sensitivity below the standard limit

I've got a USB mouse attached to my Ubuntu notebook. This mouse is (unfortunately) really sensitive, and so it sometimes gets hard to hit small icons with the mouse pointer. This is really a hardware issue, it's not a bug and it's not Ubuntu's/gnome's fault. Still, I would very much like to this issue through software (solving through hardware would imply buying a new mouse).

Back in Windows, if I set the sensitivity as really low it was comfortable enough. In Ubuntu, even the lowest sensitivity and acceleration available (in the System>Prerences>Mouse menu) is still frustrating. How can I decrease it below the default minimum?

I tried xset, but it seems xset only deals with acceleration and threshold, but not actual sensitivity.

I have a Razer DeathAdder mouse and like in your case, the sensitivity/acceleration are too high even if I put them at the lowest level in the mouse preferences. So to solve this problem, I used the xinput command.

First, you will need your mouse ProductName and ID:

xinput list
...
 Razer Razer DeathAdder                     id=8    [slave  pointer  (2)]
...

Then you set the constant deceleration level that suits your needs with this command:

xinput set-prop 8 "Device Accel Constant Deceleration" 3
# 8 = DEVICE_ID
# 3 = LEVEL (factor) Higher = Slower.

To make the config persistent (and make it system wide), you will need to edit your xorg.conf (/etc/X11/xorg.conf).

Section "InputClass"
   Identifier      "Razer"                    # Whatever you want.

   MatchProduct    "Razer Razer DeathAdder"   # Product name from xinput list.
   Option          "ConstantDeceleration" "3" # The same value as xinput.
EndSection

Once you reboot, you should have the same result as the xinput command.

Let me know if it helps.