Comment 9 for bug 1504220

Yesterday I installed nvidia driver 355.11 update from the "ubuntu fresh graphics"-PPA and the problem seems to be fixed. I can switch via "prime select" and login via light-dm works fine on nvidia.
There's only one flaw beloging to screen postioning but this is a new issue and should not be mixed with this problem.
For me this issue could be marked as fixed and closed.

Source for nvidia-355.11:
https://launchpad.net/~graphics-drivers/+archive/ubuntu/ppa/+sourcepub/5646652/+listing-archive-extra