Changing the resolution of the mouse will make it seem like it moves smoother on the screen. According to the x.org site not all mice and OS's can support this option. Also, try to change the value from 1600 to other values like possibly 800 or 400.
In the file /etc/X11/xorg.conf put the following line in the section “InputDevice” with the other mouse settings.
Option "Resolution" "1600"
Then restart X.