I have been facing this issue from the last week after some update. Whenever my laptop wakes up from suspend state it just shows me a blank screen. Regardless of whatever I do(move my mouse, press keyboard buttons) it just refuses to wake up. I am forced to do a restart and lose all my unsaved files. Has this issue been reported for Ubuntu 12.04?
I am using a Lenovo X200 with Intel Mobile 4 Series Graphics Chipset. Please let me know if any body has found a fix for this.