I actually found that if I selected UEFI boot instead of legacy boot I could run the live-usb stick.
I was unable to reproduce the problem when running from the live-usb when trying out vivid. However it turns out that I cannot reproduce the issue when running from a live-usb loaded with trusty either. In both instances I attempted to recreate the problem by rapidly switching users repeatedly for 5 minutes - when running from my installed system I am always able to reproduce the issue in less than this amount of time. When running from my installed system there is always a brief (jarring) context switch in which the screen temporarily blanks out before coming back up even when the problem doesn't occur. When running from the live- usb (trusty or vivid) the transition between users is pretty seamless: more like a workspace switch. I'm wondering what the difference is between the live-usb and installed environments (drivers, configuration, etc.) and if knowing that could give some insight into fixing the issue. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1437719 Title: [Dell Inspiron 5547] Black Screen on user switch To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/xorg/+bug/1437719/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs