synclient -m var doesn't work and how to fix the problem

synclient -m 100 will report the error message "can't access shared memory SHMConfig disabled?" under Ubuntu 10.10.

The solution is simple, type in the console:

sudo gedit /etc/X11/xorg.conf

and add the line below (if xorg.conf doesn't exist, just create it with lines below):

Section "InputClass"

Identifier "enable synaptics SHMConfig"

MatchIsTouchpad "on"

MatchDevicePath "/dev/input/event*"

Option "SHMConfig" "on"

EndSection

Save the file and reboot!

Now, the command synclient -m 100 should print something like that:

time x y z f w l r u d m multi gl gm gr gdx gdy

62.283 3304 3177 77 1 4 0 0 0 0 0 00000000 0 0 0 0 0

62.383 3240 3173 81 1 4 0 0 0 0 0 00000000 0 0 0 0 0

62.483 3206 3162 81 1 4 0 0 0 0 0 00000000 0 0 0 0 0

62.583 1 5855 2 1 5 0 0 0 0 0 00000000 0 0 0 0 0

62.684 1 5855 0 0 0 0 0 0 0 0 00000000 0 0 0 0 0

Weird results when 2 fingers touch the pad:

time x y z f w l r u d m multi gl gm gr gdx gdy

15.867 868 -1846 97 1 5 0 0 0 0 0 00000000 0 0 0 0 0

15.876 4885 2595 77 1 5 0 0 0 0 0 00000000 0 0 0 0 0

15.887 1380 -1846 91 1 5 0 0 0 0 0 00000000 0 0 0 0 0

15.899 4879 2608 77 1 5 0 0 0 0 0 00000000 0 0 0 0 0

15.911 2148 -1846 85 1 5 0 0 0 0 0 00000000 0 0 0 0 0

15.924 4877 2603 77 1 5 0 0 0 0 0 00000000 0 0 0 0 0

15.935 3940 -2102 92 1 5 0 0 0 0 0 00000000 0 0 0 0 0

15.947 4877 2603 77 1 5 0 0 0 0 0 00000000 0 0 0 0 0

Two fingers generate negative y coordinates! Perhaps, that explains the jumpy pointer?