[ubuntu] Upgrade to 16.04: External Monitor Flicker/Black Screen

Hello,

I updated my Ubuntu 14.04 to 16.04 LTS, and I have since had some issues with my exteal monitor. As I move my cursor to my second monitor I often get screen flicker, a brief black flash, it also flickers on my primary laptop screen when I do this. The flicker is relatively inconsistent, it happens more often than not though. Most frustratingly of all is that quite often my exteal monitor will go fully black and I will need to click on that screen or move the cursor to it to see the screen properly again. I had none of these problems with Ubuntu 14.04 and I now regret upgrading. I have looked at rollback options but I would much rather avoid this. Has anyone else experiences this? is it an issue with the compatibility of my graphics and Ub 16.04?

I'm using:

Lenovo ThinkPad T140s laptop
-Ubuntu 16.04 LTS
-processor: intel Core I5 CPU M 520@2,40GHz x 4
-graphics: Ironlake Mobile
-OS type: 64bit
-VGA compatible controller: Intel Core Processor Integrated Graphics Controller (rev 02) (prof-if 00 [VGA controller])

Cheers,
Jon