Ubuntu 14.04 Display Freezes Occasionally

I recently installed Ubuntu 14.04. I have an NVIDIA GeForce GT 540M (1GB) graphics card, and I noticed the open source Nouveau display driver was returning error code -16 on suspend, causing the computer to immediately rewake. So I switched over to the proprietary, tested NVIDIA v331.38 driver.

This fixed the suspend problem, but now the display will occassionally freeze and stop accepting input. The computer itself doesn't freeze -- audio keeps playing and touchpad input still goes through.

For some reason, when I switch over to the terminal using Ctrl+Alt+F1 and then switch back with Ctrl+Alt+F7, the display unfreezes and everything's fine until the next freeze.

It seems the freezing happens more often if I'm using my touchpad more actively. It's only brought on by a touchpad input as well. It won't freeze on its own.

By any chance, are you using a touch pad? If so, changing the touch pad to work as a normal usb mouse will correct issues with a 'unresponsive screen.' Unfortunately, you will not be allowed to use the tap to click feature or scroll using the pad.

This is a known bug. Fortunately, there is a fix now (but you'll need to compile packages yourself). See https://bugs.launchpad.net/ubuntu/+source/nvidia-prime/+bug/1220426.