I've seen a lot of people in this situation, but every time the variables differ and so does the solution for it.
I think I have everything installed correctly. I have Nvidia GeForce 540M with Bumblebee drivers installed.
What happens is, every two times when Ubuntu starts it tells me it is running in low-end graphics mode. I say
OK and it crashes at the next window. I just restart and it starts normally.
lspci -nn | grep '\[030\]:
and the answer was:
00:02.0 VGA compatible controller : Intel Corporation 2nd Generation Core Processor Family Integrated Graphics Controller [8086:0116] (rev 09) 01:00.0 3D controller : NVIDIA Corporation GF108 [GeForce GT 540M] [10de:0df4] (rev ff)