I had been using an external monitor, an old Dell Inc. 19" with Ubuntu 14.04 for a while now, The resolution it displayed at was something like 1366x768 or 1366x1024, I can't remember exactly which one it was. However, one day when I restarted my computer, I can no longer get that resolution on the external display, and can now display a max resolution of 1024x768. Does anyone know why this might happen all of a sudden? I think it was after running a system update.