The fix you posted didn't solve my problem, so I used your idea and I came up with this fix:
1. apt-get source xserver-xorg-input-synaptics
2. sudo apt-get build-dep xserver-xorg-input-synaptics
3. cd xserver-xorg-input-synaptics*
4. gedit synaptics.c
5. go to line 1610, where you'll find:
int timeleft;
int i;
/* update hardware state in shared memory */
para->x = hw->x;
para->y = hw->y;
para->z = hw->z;
6. insert the following code right between the two blocks of code, so it looks like this:
int timeleft;
int i;
/* this is crap, but it
saves the day */
if (hw->x == 1 && hw->y == 5855)
{
hw->numFingers = 0;
hw->fingerWidth = 0;
hw->z = 0;
hw->x = HIST(0).x;
hw->y = HIST(0).y;
}
/* update hardware state in shared memory */
para->x = hw->x;
para->y = hw->y;
para->z = hw->z;
7. save & close the file
8. sudo dpkg-buildpackage
9. cd ..
10. sudo dpkg -i xserver-xorg-input-synaptics*.deb
11. restart X with CTRL+ALT+Backspace