Synaptics touchpad on my Acer 4530 stop working

i got my touchpad stop working after several hours being disabled (using Fn+F7 in my Acer 4530). i've tried many times to turn it on using the same key-combination (Fn+F7), although the touchpad indicator says it works, but the touchpad still not working

i wonder if anybody know how to fix this problem?

I had the same problem, touchpad worked for login screen but not once logged in. I got it going with

gconftool -s -t bool /desktop/gnome/peripherals/touchpad/touchpad_enabled true

pardon me i forgot to answer your responses & answers. Actually my touchpad had came back to life again. I just re-installed the X11 then after reboot it works again. I didn't know what wrong here in my system