Since today my systems seems to freeze whenever I lock it by pressing Ctrl+ALT+L and then try to unlock it. I am using a dual monitor setup I have read AskUbuntu Post to get it working, and upon trying to unlock my system one display is re-activated and one stays black. I can move the mouse pointer but cannot click or type anything and I can't unlock the system by blindly typing my password.
What can I check to resolve this problem? Could this be prompted by the "fix" I used to get the multi display setup working with my hardware?
Laptop is a DELL Latitude E5540 with an Intel HD Graphics 4400 and a NVIDIA GeForce GT 720M. I am using the Intel and everything worked fine up until today. Also I am using Gnome 3 instead of Unity, but it happens with both.
