According to this https://devtalk.nvidia.com/default/topic/766018/unix-graphics-announcements-and-news/linux-solaris-and-freebsd-driver-343-13-beta-/
Nvidia 343.13 beta may be a solution.
"Fixed a "black window" bug in Ubuntu 14.04 when using the Xinerama and Composite extensions."
According to this https:/ /devtalk. nvidia. com/default/ topic/766018/ unix-graphics- announcements- and-news/ linux-solaris- and-freebsd- driver- 343-13- beta-/
Nvidia 343.13 beta may be a solution.
"Fixed a "black window" bug in Ubuntu 14.04 when using the Xinerama and Composite extensions."