Touchpad Problem - shortly after login, it stops working

I've Ubuntu 11.10 and my problem is about the touchpad. At the beginning of my computer it's works fine, but after opening an application or a few minutes, it stops working and I have to use a USB mouse.

sudo modprobe -r psmouse && sudo modprobe psmouse

i tried this command  and now its working good....

if u have the same problem in LENOVO G560 you can try this command.