Comment 4 for bug 780357

I'm having a similar problem, but for me it happens mostly in a certain sequence: I switch off the touchpad because an external mouse is attached (via xinput). Switching back on works. Then I put my macbook pro 6,2 to sleep and unplug the mouse. When I resume working (without the external mouse) the internal mouse is sometimes locked (which I can unlock via xinput), but sometimes nothing works (not xinput, not synclient).

Then, your modprobe trick works.

That is the last resort, and xinput, gpointing-device-settings and synclient don't help.

Xinput and synclient see the same properties and the same settings. I can change these properties, but the mouse doesn't respond to my finger moving over the pad.

gpointing-device-settings changes these properties as well, but doesn't read the values 'real-time' when I change them via xinput or synclient.

TAPPING and CLICKING and TWO-FINGER scrolling DO WORK (i.e. xev reports these).