I have been bothered by this issue for few weeks already. The problem started when I upgraded to 14.04. Parts of my screen are sometimes flickering like shown on 2 videos that links I attach below:

https://www.youtube.com/watch?v=FAg2uGABXQo

https://www.youtube.com/watch?v=ANgAl28P-YE

I was trying to record it with VLC but suddenly when I start recording then ... it stops flickering :)

I have no idea where can I file a bug for this and which package it may be connected with. Please comment with what it may be connected with and how can I resolve this.

I will post any relevant information regarding the packages if need be.

I use nvidia-334 from xorg edgers package ( 334.21-0ubuntu1~xedgers14.04.1 ) but I have also tried others and it's the same issue.