[Bf-cycles] Blender 2.63a under Ubuntu 12.04 w/ Optimus - X session crash

[Jamin W. Collins]

I've recently gotten 2.63a (w/ cycles) running under Ubuntu 12.04 on an 
Optimus based system (Thinkpad W530).  I must say, I *love* the cycles 
rendering engine.  However, I am running into a rather strange behavior. 
  If I start 2.63a without the Nvidia card activated, my entire X 
session crashes.  I have no problem running 2.62 either way on this same 
system only changing the Blender version.

Blender 2.62 (both from blender.org[1] and from Ubuntu's repository) 
starts up fine on the system, with and without the Nvidia card enabled 
via optirun.

Blender 2.63a (from blender.org[2], self compiled, or from Irie's 
PPA[3]) will only successfully run with the Nvidia card enabled.  If it 
is started without the Nvidia card enabled, all binaries I've tested 
crash my entire X session.

[1] - 
http://download.blender.org/release/Blender2.62/blender-2.62-linux-glibc27-x86_64.tar.bz2
[2] - 
http://download.blender.org/release/Blender2.63/blender-2.63a-linux-glibc27-x86_64.tar.bz2
[3] - https://launchpad.net/~irie/+archive/blender