FWIW, I've had this problem too. I found a fix for this (http://ubuntuforums.org/showthread.php?t=1852081&page=4&styleid=109) is to run "synclient TouchpadOff=0" from a terminal.
Here is the dmesg output of when this last happened: [ 365.304496] psmouse.c: TouchPad at isa0060/serio1/input0 lost synchronization, throwing 4 bytes away. [ 365.827318] psmouse.c: resync failed, issuing reconnect request [ 387.700302] psmouse.c: TouchPad at isa0060/serio1/input0 lost sync at byte 4 [ 387.701885] psmouse.c: TouchPad at isa0060/serio1/input0 lost sync at byte 1 [ 387.703597] psmouse.c: TouchPad at isa0060/serio1/input0 lost sync at byte 1 [ 387.712677] psmouse.c: TouchPad at isa0060/serio1/input0 lost sync at byte 4 [ 387.715189] psmouse.c: TouchPad at isa0060/serio1/input0 lost sync at byte 1 [ 387.715193] psmouse.c: issuing reconnect request -- You received this bug notification because you are a member of Ubuntu-X, which is subscribed to xserver-xorg-input-synaptics in Ubuntu. https://bugs.launchpad.net/bugs/868400 Title: Synaptics touchpad stops working To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/gnome-settings-daemon/+bug/868400/+subscriptions _______________________________________________ Mailing list: https://launchpad.net/~ubuntu-x-swat Post to : ubuntu-x-swat@lists.launchpad.net Unsubscribe : https://launchpad.net/~ubuntu-x-swat More help : https://help.launchpad.net/ListHelp